Introduction

Abdominal pain is traditionally described by its chronicity (acute or chronic), its progression over time, its nature (sharp, dull, colicky), its distribution (by various methods, such as abdominal quadrant (left upper quadrant, left lower quadrant, right upper quadrant, right lower quadrant) or other methods that divide the abdomen into nine sections), and by characterization of the factors that make it worse, or alleviate it.

Due to the many organ systems in the abdomen, abdominal pain is a concern of general practitioners/family physicians, surgeons, internists, emergency medicine doctors, pediatricians, gastroenterologists, urologists and gynecologists. Occasionally, patients with rare causes can see a number of specialists before being diagnosed adequately (e.g., chronic functional abdominal pain).

Types and mechanisms

1. The pain associated with inflammation of the parietal peritoneum is steady and aching, and worsened by changes in the tension of peritoneum caused by pressure or positional change. It is often accompanied by tension of the abdominal muscles contracting to relieve such tension.
2. The pain associated with obstruction of the hollow viscera is often intermittent or “colicky”
3. The pain associated with abdominal vascular disturbances (thrombosis or embolism) can be sudden or gradual in onset, and can be severe or mild. Pain associated with the rupture of an abdominal aortic aneurysm may radiate to the back, flank, or genitals.
4. Pain that is felt in the abdomen may be “referred” from elsewhere (e.g., a disease process in the chest, like a subdiaphragmatic abscess, may cause pain in the abdomen), and abdominal processes can cause radiated pain elsewhere (e.g., gall bladder pain—in cholecystitis or cholelithiasis—is often referred to the shoulder).

Selected causes

* parietal peritoneal inflammation
o due to infection: inflamed or suppurative appendix in appendicitis, pelvic inflammatory disease
o due to chemical irritation: perforated gastric or peptic ulcer; pancreatitis, Mittelschmerz, ruptured ectopic pregnancy
o miscellaneous (familial Mediterranean fever)
* inflammation of bowel wall Crohn’s disease, ulcerative colitis, microscopic colitis, diverticulitis, gastroenteritis
* autoimmune: sarcoidosis, vasculitis
* mechanical obstruction of hollow viscera such as the small intestine, the appendix associated with appendicitis, the large intestine (e.g. by intussusception), the biliary tree (e.g. by gallstones), or the ureter (e.g. by urinary calculi)
* vascular disturbances (leading to ischemia): embolism, thrombosis, vascular rupture, torsional occlusion (volvulus), sickle cell anemia, left renal vein entrapment, superior mesenteric artery syndrome (nutcracker syndrome)
* abdominal wall injury/disruption: mesenteric traction, muscle trauma, muscular infection, diverticulosis (rare)
* digestive: lactose intolerance, Celiac sprue
* distention of visceral surfaces such as the hepatic or renal capsule
* referred pain from the thorax (pneumonia, coronary occlusion), the spine (radiculitis secondary to arthritis), genitals (testicular torsion)
* metabolic disturbance: lead poisoning, Black widow spider bite, uremia, diabetic ketoacidosis, porphyria, C1-esterase inhibitor deficiency, adrenal insufficiency
* neurogenic pain: tabes dorsalis, herpes zoster, Lyme disease (Lyme radiculitis or Bannwarth syndrome)
* functional pain, Irritable Bowel Syndrome (affecting up to 20% of the population, IBS is the most common cause of recurrent, intermittent abdominal pain)
* reproductive organs (in women): mittelschmerz, torsion of the ovary, ectopic pregnancy,
* pelvic inflammatory disease
* endometriosis
* Post-surgical adhesions
* Diarrhea
* meningitis

Acute Abdomen

Acute abdomen can be defined as severe, persistent abdominal pain of sudden onset that is likely to require surgical intervention to treat its cause. The pain may frequently be associated with nausea and vomiting, abdominal distention, fever and signs of shock.

Selected causes of acute abdomen

* Traumatic : blunt or perforating trauma to the stomach, bowel, spleen, liver, or kidney
* Inflammatory :
o Infections such as appendicitis, cholecystitis, pancreatitis, pyelonephritis, pelvic inflammatory disease, hepatitis, mesenteric adenitis, or a subdiaphragmatic abscess
o Perforation of a peptic ulcer, a diverticulum, or the caecum
o Complications of inflammatory bowel disease such as Crohn’s disease or ulcerative colitis
* Mechanical :
o Small bowel obstruction secondary to adhesions caused by previous surgeries, intussusception, hernias, benign or malignant neoplasms
o Large bowel obstruction caused by colorectal cancer, inflammatory bowel disease, volvulus, fecal impaction or hernia
* Vascular : occlusive intestinal ischemia, usually caused by thromboembolism of the superior mesenteric artery

Recurrent Abdominal Pain in Female Adolescents

Recurrent abdominal pain (RAP) occurs in 5–15% of female children 6–19 years old. In a community-based study of middle and high school students, 13–17% had weekly abdominal pain. Using criteria for irritable bowel syndrome (IBS), 14% of high school students and 6% of middle school students fit the criteria for adult IBS. As with other difficult to diagnose chronic medical problems, patients with RAP [Recurrent Abdominal Pain] account for a very large number of office visits and medical resources in proportion to their actual numbers.

Etiology

* Gynecologic Etiologies
o Dysmenorrhea
o Endometriosis
o Müllerian abnormalities
o Pelvic Inflammatory Disease
o Ovarian Abnormalities

* Abdominal Etiologies

Medical Assessment

When a physician assesses a patient to determine the etiology and subsequent treatment for abdominal pain the patients history of the presenting complaint and physical examination should derive a diagnosis in over 90% of cases.

It is important also for a physician to remember that abdominal pain can be caused by problems outside the abdomen, especially heart attacks and pneumonias which can occasionally present as abdominal pain.

Investigations that would aid diagnosis include

* Blood tests including Full Blood Count, Electrolytes, Urea, Creatinine, Liver function tests, pregnancy test and lipase.
* Urinalysis
* Imaging including erect Chest X-ray and plain films of the abdomen
* An electrocardiograph to rule out a heart attack which can occasionally present as abdominal pain

If diagnosis remains unclear after history, examination and basic investigations as above then more advanced investigations may reveal a diagnosis. These as such would include

* Computed Tomography of the Abdomen/Pelvis
* Abdominal or Pelvic ultrasound
* Endoscopy and Colonoscopy (not used for diagnosing acute pain)

Causes

Nausea is not an illness itself; it is rather a possible case of several conditions, many of which are not related to the stomach at all. In fact, more often than not nausea indicates a condition somewhere else in the body rather than in the stomach itself. An example of this is travel sickness, which is due to confusion between perceived movement and actual movement. Our sense of equilibrium lies in the ear and works together with eyesight. When these two don’t “agree” to what extent the body is actually moving the symptom is presented as nausea even though the stomach itself has nothing to do with the situation. Nausea is also an adverse effect of many drugs.

In medicine, nausea is a particular problem during some chemotherapy regimens and following general anaesthesia. Nausea is also a common symptom of pregnancy. Even though nausea is generally seen as an indication that something is wrong, experiencing it during pregnancy is quite normal, and should not be considered an immediate cause for alarm.
Treatment

While short-term nausea and vomiting are generally harmless, they may sometimes indicate a more serious condition, such as Celiac Disease. When associated with prolonged vomiting, it may cause dangerous levels of dehydration and/or electrolyte imbalances.

Symptomatic treatment for nausea and vomiting may include short-term avoidance of solid food. This is usually easy as nausea is nearly always associated with loss of appetite. Dehydration may require rehydration with oral or intravenous electrolyte solutions. Oral rehydration (drinking water) is safer and simpler in most cases.

There are many antiemetics (drugs to suppress nausea and vomiting), although researchers continue to look for more effective treatments. Also available are a variety of noninvasive, mechanical devices used to suppress nausea due to motion sickness, but these products are seldom tested in a laboratory setting.

The medical branch investigating vomiting, emetics and antiemetics is called emetology.

Mechanism

Vomiting center

Vomiting is coordinated in the vomiting center in the lateral medullary reticular formation in the medulla. Receptors on the floor of the fourth ventricle of the brain represent a chemoreceptor trigger zone, stimulation of which can lead to vomiting. The chemoreceptor zone lies outside the blood-brain barrier, and can therefore be stimulated by blood-borne drugs that can stimulate vomiting, or inhibit it.

There are various sources of input to the vomiting center:

* The chemoreceptor trigger zone at the base of the fourth ventricle has numerous dopamine D2 receptors, serotonin 5-HT3 receptors, opioid receptors, Acetylcholine receptors, and receptors for substance P. Stimulation of different receptors are involved in different pathways leading to emesis, in the final common pathway substance P appears to be involved.[1]
* The vestibular system which sends information to the brain via cranial nerve VIII (vestibulocochlear nerve). It plays a major role in motion sickness and is rich in muscarinic receptors and histamine H1 receptors.
* Cranial nerve X (vagus nerve), which is activated when the pharynx is irritated, leading to a gag reflex.
* Vagal and enteric nervous system inputs that transmit information regarding the state of the gastrointestinal system. Irritation of the GI mucosa by chemotherapy, radiation, distention or acute infectious gastroenteritis activates the 5-HT3 receptors of these inputs.
* The CNS mediates vomiting arising from psychiatric disorders and stress.

Vomiting act

The vomiting act encompasses three types of outputs initiated by the medulla: Motor, parasympathetic nervous system (PNS) and sympathetic nervous system (SNS). Collectively, they are as follows:

* Increased salivation to protect the enamel of teeth from stomach acids (excessive vomiting does lead to caries). This is part of the PNS output.
* Retroperistalsis, starting from the middle of the small intestine, sweeping up the contents of the digestive tract into the stomach, through the relaxed pyloric sphincter.
* A lowering of intrathoracic pressure (by inspiration against a closed glottis), coupled with an increase in abdominal pressure as the abdominal muscles contract, propels stomach contents into the esophagus without involvement of retroperistalsis. The lower esophageal sphincter relaxes. This is part of the motor output, and it is also important to note that the stomach itself does not contract in the process of vomiting.
* Vomiting is ordinarily preceded by retching.
* Vomiting also initiates a SNS response causing both sweating and increased heart rate.

The neurotransmitters that regulate vomiting are poorly understood, but inhibitors of dopamine, histamine and serotonin are all used to suppress vomiting, suggesting that these play a role in the initiation or maintenance of a vomiting cycle. Vasopressin and neurokinin may also participate.

Content

Since the stomach secretes acid, vomit contains a high concentration of hydronium ions and is thus strongly acidic. Recent food intake will be reflected in the gastric vomit.

The content of the vomitus (vomit) may be of medical interest. Fresh blood in the vomit is termed hematemesis (“blood vomiting”). Old blood bears resemblance to coffee grounds (as the iron in the blood is oxidized), and when this matter is identified the term “coffee ground vomiting” is used. Bile can enter the vomit during subsequent heaves due to duodenal contraction if the vomiting is severe. Fecal vomiting is often a consequence of intestinal obstruction, and is treated as a warning sign of this potentially serious problem (“signum mali ominis”); such vomiting is sometimes called “miserere”.

If the vomiting reflex continues for an extended period of time with no appreciable vomitus, the condition is known as non-productive emesis or dry heaves, which can become both extremely painful and debilitating.

Complications of vomiting

Aspiration of vomitus

Vomiting can be very dangerous if the gastric content gets into the respiratory tract. Under normal circumstances the gag reflex and coughing will prevent this to occur, however these protective reflexes are compromised in persons under narcotic influences such as alcohol or anesthesia. The individual may choke and asphyxiate or suffer an aspiration pneumonia.

Dehydration and electrolyte imbalance

Prolonged and excessive vomiting will deplete the body of water (dehydration) and may alter the electrolyte status. The loss of acids leads to metabolic alkalosis (increased blood pH), and the electrolyte imbalance shows hypokalemia (potassium depletion) and hypochloremia (chlorine depletion). The hypokalemia is an indirect result of the kidney compensating for the loss of acid. With the loss of intake of food the individual will become cachectic.

Causes

Vomiting may be due to a large number of causes, and protracted vomiting has a long differential diagnosis.

Digestive tract

Causes in the digestive tract:

* Gastritis (inflammation of the gastric wall, usually by viruses)
* Pyloric stenosis (in babies – this typically causes a very forceful “projectile vomiting” and is an indication for urgent surgery)
* Bowel obstruction
* Acute abdomen and/or peritonitis
* Ileus
* Cholecystitis, pancreatitis, appendicitis, hepatitis
* In children, it can be caused by an allergic reaction to cow’s milk proteins (milk allergy)

Sensory system and brain

Causes in the sensory system:

* Movement: motion sickness (which is caused by overstimulation of the labyrinthine canals of the ear)
* Ménière’s disease

Causes in the brain:

* Concussion
* Intoxication with alcohol (being sick whilst being drunk or being sick the next morning suffering from the after-effects, i.e. the hangover).)
* Cerebral hemorrhage
* Brain tumors
* Benign intracranial hypertension and hydrocephalus

Metabolic disturbances (these may irritate both the stomach and the parts of the brain that coordinate vomiting):

* Hypercalcemia (high calcium levels)
* Uremia (urea accumulation, usually due to renal failure)
* Adrenal insufficiency
* Hypoglycemia

Pregnancy:

* Hyperemesis, Morning sickness

Opioids, selective serotonin reuptake inhibitors, many chemotherapy drugs, and a host of other drugs may cause nausea and vomiting.

Other

* Self-induced
o Eating disorders (anorexia nervosa or bulimia nervosa)
o Sexual fetish (emetophilia)
o To remove a poison in case such has been ingested (some poisons should not be vomited as they may be more toxic when inhaled or aspirated; it is generally considered better to ask for help before inducing vomiting)
o Some people who are engaged in binge drinking will induce vomiting in order to make room in their stomachs for further alcohol consumption. In the United Kingdom, this practice is known as tactical chundering, and as boot and rally or pulling the trigger in the United States.
* After surgery (postoperative nausea and vomiting)
* Disagreeable sights or smells, such as decayed matter, others’ vomit, etc.
* Extreme pain, such as intense headache or myocardial infarction (heart attack)
* Violent emotions (including laughing)
* Cyclic vomiting syndrome (a poorly understood condition with attacks of vomiting)
* High doses of ionizing radiation will sometimes trigger a vomit reflex in the victim.
* Violent fits of coughing
* Nervousness

Related medication

Emetics

An emetic, such as Syrup of Ipecac, is a substance that induces vomiting when administered orally or by injection. An emetic is used medically where a substance (typically poison) has been ingested and must be expelled from the body immediately. Inducing vomiting can remove the substance before it is absorbed into the body. Ipecac abuse can lead to detrimental health effects.

Antiemetics

An antiemetic is a drug that is effective against vomiting and nausea. Antiemetics are typically used to treat motion sickness and the side effects of some opioid analgesics and chemotherapy directed against cancer.

Antiemetics act by inhibiting the receptor sites associated with emesis. Hence, anticholinergics, antihistamines, dopamine antagonists, serotonin antagonists and cannabinoids are used as anti-emetics.

Social implications
Vomit found on pavement, suggesting unexpected vomiting occurred. Vomiting resulting from social drinking is often sudden and uncontrollable.
Vomit found on pavement, suggesting unexpected vomiting occurred. Vomiting resulting from social drinking is often sudden and uncontrollable.

Nausea inducement in groups

It is quite common that when one person vomits, others nearby will become nauseated, particularly when smelling the vomit of others, often to the point of vomiting themselves. It is believed that this is an evolved trait among primates. Many primates in the wild will tend to browse for food in small groups. Should one member of the party react adversely to some ingested food it may be advantageous (in a survival sense) for other members of the party also to vomit. This tendency in human populations has been observed at drinking parties, where excessive consumption of alcoholic beverages may result in a number of party members vomiting nearly simultaneously, this being triggered by the initial vomiting of a single member of the party. This phenomenon has been touched on in popular culture: notorious instances appear in the films The Meaning of Life (1983) and Stand By Me (1986), while in the computer game Theme Hospital, it is referred to as a ‘vomit wave’ and can spread through the hospital quickly.

There have also been documented cases of a single ill and vomiting individual inadvertently causing others to do so, when they are especially fearful of also becoming ill, through a form of mass hysteria.

Context

Most people try to contain their vomit by vomiting into a sink, toilet, or trash can, as both the act and the vomit itself are widely considered embarrassing; vomit is also difficult to clean. On airplanes and boats, special bags are supplied for sick passengers to vomit into. Alternatively, a special disposable bag is available containing absorbent material that solidifies the vomit quickly, making it convenient and safe to keep (leakproof, puncture resistant, odorless) until there is an opportunity to dispose of it conveniently.

People who vomit chronically (e.g. as part of an eating disorder such as bulimia nervosa) may devise various ways to hide this abnormality.

Causes
Diagram of the human gastrointestinal tract.
Diagram of the human gastrointestinal tract.

This condition can occur as a symptom of infection, allergy, food intolerance, foodborne illness and/or extreme excesses of Vitamin C and/or magnesium and may be accompanied by abdominal pain, nausea and vomiting. Temporary diarrhea can also result from the ingestion of laxative medications or large quantities of certain foods like prunes with laxative properties. There are other conditions which involve some but not all of the symptoms of diarrhea, and so the formal medical definition of diarrhea involves defecation of more than 200 grams per day (though formal weighing of stools to determine a diagnosis is never actually carried out).

Diarrhea occurs when insufficient fluid is absorbed by the colon. As part of the digestion process, or due to fluid intake, food is mixed with large amounts of water. Thus, digested food is essentially liquid prior to reaching the colon. The colon absorbs water, leaving the remaining material as a semisolid stool. If the colon is damaged or inflamed, however, absorption is inhibited, and watery stools result.

Diarrhea is most commonly caused by viral infections or bacterial toxins. In sanitary living conditions and with ample food and water available, an otherwise healthy patient typically recovers from the common viral infections in a few days and at most a week. However, for ill or malnourished individuals diarrhea can lead to severe dehydration and can become life-threatening without treatment.

Diarrhea can also be a symptom of more serious diseases, such as dysentery, cholera, or botulism, and can also be indicative of a chronic syndrome such as Crohn’s disease. Though appendicitis patients do not generally have diarrhea, it is a common symptom of a ruptured appendix. It is also an effect of severe radiation sickness.

Diarrhea can also be caused by dairy intake in those who are lactose intolerant.

Symptomatic treatment for diarrhea involves the patient consuming adequate amounts of water to replace that loss, preferably mixed with electrolytes to provide essential salts and some amount of nutrients. For many people, further treatment is unnecessary. The following types of diarrhea generally indicate medical supervision is desirable:

* Diarrhea in infants;
* Moderate or severe diarrhea in young children;
* Diarrhea associated with blood;
* Diarrhea that continues for more than 2 weeks;
* Diarrhea that is associated with more general illness such as non-cramping abdominal pain, fever, weight loss, etc;
* Diarrhea in travelers, since they are more likely to have exotic infections such as parasites;
* Diarrhea in food handlers, because of the potential to infect others;
* Diarrhea in institutions such as hospitals, child care centers, or geriatric and convalescent homes.

Mechanism

To expel the contents of the lower digestive tract, the fluidity of the contents of the small and large intestines is increased. Active transport of Na+ back into the gut initiates a reverse sodium transport. This causes both Cl- and HCO3 to follow passively, as well as water. Now in the intestines, the water dilutes toxins as well as triggering contractions of the intestine due to increase in intestinal distension. These contractions push the contents of the lower GI tract towards and out of the anal canal. Medications such as loperamide are designed to prevent such contractions in response to the distension, and should not be used to prevent diarrhea. Such inhibition actually prolongs the infection or irritation, and can cause a worsening over time because the evacuation of the bowel contents has been delayed.

Types of Diarrhea

There are at least four types of diarrhea: secretory diarrhea, osmotic diarrhea, motility-related diarrhea, and inflammatory diarrhea.

Secretory diarrhea

Secretory diarrhea means that there is an increase in the active secretion, or there is an inhibition of absorption. There is little to no structural damage. The most common cause of this form of this type of diarrhea is a cholera toxin that stimulates the secretion of anions, especially Chloride ions. Therefore, to maintain a charge balance in the lumen, Sodium is carried with it, along with water.

Osmotic diarrhea

Osmotic diarrhea occurs when there is a loss of water due to a heavy osmotic load. This can occur when there is maldigestion (e.g., pancreatic disease or Celiac disease), where the nutrients are left in the lumen, which pulls water into the lumen.

Motility-related diarrhea

Motility-related diarrhea occurs when the motility of the gastrointestinal tract is abnormal. If the food moves too quickly, there is not enough contact time between the food and the membrane, meaning that there is not enough time for the nutrients and water to be absorbed. This can follow a vagotomy or diabetic neuropathy.

Inflammatory diarrhea

Inflammatory diarrhea occurs when there is damage to the mucosal lining or brush border, which leads to a passive loss protein-rich fluids, and a decreased ability to absorb these lost fluids. Features of all three of the other types of diarrhea can be found in this type of diarrhea. It can be caused by bacterial infections, viral infections, parasitic infections, or autoimmune problems such as inflammatory bowel disease.

Acute diarrhea

This may be defined as diarrhea that lasts less than 4 weeks, and is also called enteritis.

This can nearly always be presumed to be infective, although only in a minority of cases is this formally proven.

With cases of acute diarrhea, it is often reasonable to reassure a patient, ensure adequate fluid intake, and wait and see. In more severe cases, or where it is important to find the cause of the illness, stool cultures are instituted.

The most common organisms found are Campylobacter (an organism of animal origin), Salmonella (also often of animal origin), Cryptosporidium (animal origin), Giardia lamblia (lives in water). Shigella (dysentery) is less common, and usually human in origin. Cholera is rare in Western countries. It is more common in travelers and is usually related to contaminated water (its ultimate source is probably sea water). Escherichia coli is probably a very common cause of diarrhea, especially in travelers, but it can be difficult to detect using current technology. The types of E. coli vary from area to area and country to country.

Viruses, particularly rotavirus, are common in children. (Viral diarrhea is probably over-diagnosed by non-doctors). Norwalk virus can also cause these symptoms.

Toxins and food poisoning can cause diarrhea. These include staphylococcal toxin (often from milk products due to an infected wound in workers), and Bacillus cereus. Often “food poisoning” is really Salmonella infection. Diarrhea can also be caused by ingesting foods that contain indigestible material, for instance, escolar and olestra.

Parasites and worms sometimes cause diarrhea but are often accompanied by weight loss, irritability, rashes or anal itching. The most common is pinworm (mostly a nuisance rather than a severe medical illness). Other worms, such as hookworm, ascaria, and tapeworm are more medically significant and may cause weight loss, anemia, general unwellness and allergy problems. Amoebic dysentery due to Entamoeba histolytica is an important cause of bloody diarrhea in travelers and also sometimes in western countries. It requires appropriate and complete medical treatment.

Chronic diarrhea

Infective diarrhea

It is not uncommon for diarrhea to persist. Diarrhea due to some organisms may persist for years without significant long term illness. More commonly the diarrhea slowly ameliorates but the patient becomes a carrier (harbors the infection without illness). This is often an indication for treatment, especially in food workers or institution workers.

Parasites (worms and amoeba) should always be treated. Salmonella is the most common persistent bacterial organism in humans.

Malabsorption

These tend to be more severe medical illnesses. Malabsorption is the inability to absorb food, mostly in the small bowel but also due to the pancreas.

Causes include celiac disease (intolerance to gluten, a wheat product), lactose intolerance (Intolerance to milk sugar, common in non-Europeans), fructose malabsorption, pernicious anemia (impaired bowel function due to the inability to absorb vitamin B12), loss of pancreatic secretions (may be due to cystic fibrosis or pancreatitis), short bowel syndrome (surgically removed bowel), radiation fibrosis (usually following cancer treatment), and other drugs such as chemotherapy.

Inflammatory bowel disease

The two overlapping types here are of unknown origin:

* Ulcerative colitis is marked by chronic bloody diarrhea and inflammation mostly affects the distal colon near the rectum.
* Crohn’s disease typically affects fairly well demarcated segments of bowel in the colon and often affects the end of the small bowel.

Irritable Bowel Syndrome

Irritable Bowel Syndrome. Symptoms defining IBS: abdominal discomfort or pain relieved by defecation and unusual stool (diarrhea or constipation or both) or stool frequency, for at least 3 days a week over the previous 3 months.[2] IBS symptoms can be present in patients with a variety of conditions including food allergies, infective diarrhea, celiac, and inflammatory bowel diseases. Treating the underlying condition (celiac disease, food allergy, bacterial dysbiosis, etc.) usually resolves the diarrhea.[3] IBS can cause visceral hypersensitivity. While there is no direct treatment for undifferentiated IBS, symptoms, including diarrhea, can sometimes be managed through a combination of dietary changes, soluble fiber supplements, and/or medications.

Other important causes

* Ischaemic bowel disease. This usually affects older people and can be due to blocked arteries.
* Bowel cancer: Some (but not all) bowel cancers may have associated diarrhea. Cancer of the large colon is most common.
* Hormone-secreting tumors: some hormones (e.g. serotonin) can cause diarrhea if excreted in excess (usually from a tumor).
* Bile salt diarrhea: excess bile salt entering the colon rather than being absorbed at the end of the small intestine can cause diarrhea, typically shortly after eating. Bile salt diarrhea is a possible side-effect of gallbladder removal. It is usually treated with cholestyramine, a bile acid sequestrant.

Alcohol

Chronic diarrhea can be caused by chronic ethanol ingestion [1]. Consumption of alcohol affects the body’s capability to absorb water – this is often a symptom that accompanies a hangover after a heavy drinking session. The alcohol itself is absorbed in the intestines and as the intestinal cells absorb it, the toxicity causes these cells to lose their ability to absorb water. This leads to an outpouring of fluid from the intestinal lining, which is in turn poorly absorbed. The diarrhea usually lasts for several hours until the alcohol is detoxified and removed from the digestive system. Symptoms range from person to person and are influenced by both the amount consumed as well as physiological differences.

Treatment of diarrhea
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Nurses encouraging this patient to drink an Oral Rehydration Solution to improve dehydration he acquired from cholera.Courtesy:Centers for Disease Control and Prevention
Nurses encouraging this patient to drink an Oral Rehydration Solution to improve dehydration he acquired from cholera.
Courtesy:Centers for Disease Control and Prevention

1. Keep hydrated with properly balanced electrolytes. This is the most appropriate treatment in most cases of diarrhea, even dysentery. Large amounts of electrolytes are found in the sports drinks Gatorade and Powerade, so it is a wise choice to drink these while ill with diarrhea. Consuming large amounts of water unbalanced by dietary electrolytes may result in a dangerous electrolytic imbalance which in rare cases can prove fatal (cf. water poisoning).
2. Try eating more often but smaller portions. Eat regularly. Don’t eat or drink too quickly.
3. Intravenous fluids or a “drip”: Sometimes, especially in children, dehydration can be life-threatening and intravenous fluid may be required.
4. Oral rehydration therapy: Taking a sugar/salt solution, which can be absorbed by the body.
5. Opioids and their analogs should not be used for infectious diarrhea as they are said to prolong the illness and may increase the risk of a carrier state. Opioids are the most effective antidiarrheals available. Their principal method of action is to inhibit peristalsis. Loperamide, also known as Imodium, is the most commonly used antidiarrheal. Loperamide is chemically related to the drug meperidine or Demerol, but does not cross the blood-brain barrier and does not appear to induce tolerance or dependence. Other opioids used to control diarrhea (in increasing order of strength) are: Lomotil (diphenoxylate with atropine); Motofen (difenoxin with atropine); codeine; paregoric (camphorated tincture of opium), opium tincture (laudanum); and morphine. The most potent opioids are generally reserved for chronic diarrhea (e.g., from complications of AIDS).
6. Antibiotics: antibiotics may be required if a bacterial cause is suspected and the patient is medically ill. They are sometimes also indicated for workers with carrier states in order to clear up an infection so that the person can resume work. Parasite-related diarrhea (e.g. giardiasis) require appropriate antibiotics. Antibiotics are not routinely used, as the cause is rarely bacterial and antibiotics may further upset intestinal flora and worsen rather than improve the diarrhea. Clostridium difficile-associated diarrhea and pseudomembranous colitis is often caused by antibiotic use.
7. Dietary manipulation: in particular, patients with celiac disease should avoid wheat products. Patients with Irritable Bowel Syndrome can make dietary changes to prevent the over-reaction of their gastrocolic reflex that results in diarrhea. Having soluble fiber foods and supplements, substituting soy or rice products for dairy, being careful with fresh fruits and vegetables that are high in insoluble fiber, and eating regular small amounts can all help to lessen the symptoms of IBS[4]. Foods and beverages to be avoided or minimized include red meat, oily or fatty (and fried) products, dairy (even when there is no lactose intolerance), solid chocolate, coffee (regular and decaffeinated), alcohol, carbonated beverages (especially those also containing sorbitol) and artificial sweeteners[4]. Several of the most common dietary triggers are well-established by clinical studies at this point; research has shown that IBS patients are hypersensitive to fats, insoluble fibers, and fructose[5] [6] [7].
8. Hygiene and isolation: Hygiene is important in limiting spread of the disease.
9. It is claimed that some fruit, such as bananas, mangoes, papaya, guava and pineapple may have positive effects for this condition . Bananas have the merits of being easily obtainable, and they are unlikely to have any other significant unwanted side effects. Bananas and mangoes are high in soluble fiber, which can help regulate water content in the bowel and alleviate diarrhea. Mucilage, which can be obtained in capsule form, may be helpful for the same reason. Mucilage can also be used as cereal for babies, as it is easily digested. The high acid content of pineapple may make this food a bad choice for people suffering from chronic diarrhea.
10. A common non-pharmaceutical based treatment is to ingest only clear liquids for 24 hours (sports drinks, soup broth, popsicles, jello, ginger ale) followed by the slow introduction of a bland diet often described by the mnemonic BRAT for Bananas, Rice, Applesauce, and Toast.
11. In the third world a common way to stop diarrhea is to take one handful of rice and an equal quantity of water, place in a pot, bring to a boil for 3 to 5 minutes. Pouring off and drinking the fluid usually stops diarrhea – even faster than some First World over-the-counter “remedies.” Water can be added to the remaining hard rice which is to be eaten – once cooked – by the patient.
12. A common remedy in Latin America, particularly Costa Rica, Panama and Nicaragua, is to mix a half glass of water with two spoons of prepared starch, a half spoon of sugar and the juice of a lemon and drink it; the starch is supposed to calm the intestines.

Signs and symptoms
Types 1 and 2 on the Bristol Stool Chart indicate constipation
Types 1 and 2 on the Bristol Stool Chart indicate constipation

In common constipation, the stool is hard and difficult to pass. Usually, there is an infrequent urge to void. Straining to pass stool may cause hemorrhoids and anal fissures. In later stages of constipation, the abdomen may become distended and diffusely tender and crampy, occasionally with enhanced bowel sounds.

While many feel that one should have a bowel movement every day, some people may only feel the need to defecate one to three times a week. Medical authorities seem to accept wide variations in toilet frequency as long as this does not cause any other symptoms. Defecating depends on dietary habits, exercise, fluid intake, and various other factors.

Severe cases (“fecal impaction”) may feature symptoms of bowel obstruction (vomiting, very tender abdomen) and “paradoxical diarrhea”, where soft stool from the small intestine bypasses the impacted matter in the colon.

Constipation in children can lead to soiling (enuresis and encopresis).

Diagnosis

The diagnosis of constipation is essentially made from the patient’s description of the symptoms. Bowel movements that are difficult to pass, very firm, or made up of small rabbit-like pellets qualify as constipation, even if they occur every day. Other symptoms related to constipation can include bloating, distention, abdominal pain, or a sense of incomplete emptying.

Inquiring about dietary habits may reveal a low intake of dietary fiber or inadequate amounts of fluids. Constipation as a result of poor ambulation or immobility should be considered in the elderly. Constipation may arise as a side effect of medications (especially antidepressants and opiates). Rarely, other symptoms suggestive of hypothyroidism may be elicited.

During physical examination, scybala (manually palpable lumps of stool) may be detected when a diagnostician presses on the abdomen. Rectal examination gives an impression of the anal sphincter tone and whether the lower rectum contains any feces or not; if so, then suppositories or enemas may be considered. Otherwise, oral medication may be required. Rectal examination also gives information on the consistency of the stool, presence of hemorrhoids, and whether any tumors or abnormalities are present.

X-rays of the abdomen, generally only performed on hospitalized patients, may reveal impacted fecal matter in the colon, and confirm or rule out other causes of similar symptoms.

Chronic constipation (symptoms present for more than 3 months at least 3 days per month) associated with abdominal discomfort is often diagnosed as irritable bowel syndrome (IBS) when no obvious cause is found. Physicians caring for patients with chronic constipation are advised to rule out obvious causes through normal testing.[1]

Causes

The main causes of constipation include:

* Hardening of the feces
o Insufficient intake of dietary fiber
o Dehydration
o Medication, e.g. diuretics and those containing iron, calcium, aluminium
* Paralysis or slowed transit, where peristaltic action is diminished or absent, so that feces are not moved along
o Hypothyroidism (slow-acting thyroid gland)
o Hypokalemia
o Injured anal sphincter (patulous anus)
o Medications, such as loperamide, opioids (e.g. codeine & morphine) and certain antidepressants
o Severe illness due to other causes; occasionally colds or flu
o Acute porphyria (a very rare inherited condition)
o Lead poisoning
* Dyschezia syn(usually the result of suppressing defecation)
* Constriction, where part of the intestine or rectum is narrowed or blocked, not allowing feces to pass
o Strictures
o Diverticula
o Tumors, either of the bowel or surrounding tissues
* Psychosomatic constipation, based on anxiety or unfamiliarity with surroundings.
o Functional constipation
o Constipation-predominant irritable bowel syndrome, characterized by a combination of constipation and abdominal discomfort and/or pain[2]

Treatment

In people without medical problems, the main intervention is the increase of fluids (preferably water) and dietary fiber. The latter may be achieved by consuming more vegetables and fruit, whole meal bread and by adding linseeds to one’s diet. The routine non-medical use of laxatives is to be discouraged as this may result in bowel action becoming dependent upon their use. Enemas can be used to provide a form of mechanical stimulation.

Laxatives may be necessary in people in whom dietary intervention is not effective or inappropriate. Stimulant laxatives (e.g. senna) are generally avoided, as they may worsen crampy sensations commonly experienced in constipation. In various conditions (such as the use of codeine or morphine), combinations of hydrating (e.g. lactulose or glycols), bulk-forming (e.g. psyllium) and stimulant agents may be necessary. Many of the products are widely available over-the-counter.

Enemas and clysters are a remedy occasionally used for hospitalized patients in whom the constipation has proven to be severe, dangerous in other ways, or resistant to laxatives. Sorbitol, glycerin and arachis oil suppositories can be used. Severe cases may require phosphate solutions introduced as enemas.

Constipation that resists all the above measures requires physical intervention. Manual disimpaction (the physical removal of impacted stool) is done under sedation or a general anesthetic—this avoids pain and loosens the anal sphincter.

In alternative and traditional medicine, colonic irrigation, enemas, exercise, diet and herbs are used to treat constipation.

Constipation is usually easier to prevent than to treat. The relief of constipation with osmotic agents, i.e. lactulose, Polyethyleneglycol(PEG), or magnesium salts, should immediately be followed with prevention using increased fiber(fruits and vegetables) and a nightly decreasing dose of osmotic laxative. With continuing narcotic use, for instance, nightly doses of osmotic agents can be given indefinitely (without harm) to cause a daily bowel movement.

List of signs and symptoms of gastroenterological diseases:

* constipation
* diarrhea
* vomiting
* nausea
* abdominal pain

List of research fields in Gastroenterology:

* Neurogastroenterology
* Motility