Diarrhea

2007-08-09T20:10:00.000-07:00

Diarrhea
From Wikipedia, the free encyclopedia

In medicine, diarrhea, also spelled diarrhoea, refers to frequent loose or liquid bowel movements. Acute diarrhea due to viral gastroenteritis is a common cause of death in developing countries and is a major cause of infant death worldwide.

Look up diarrhea in Wiktionary, the free dictionary.
DiarrheaClassification & external resources

Types 4[citation needed]-7 on the Bristol Stool Chart are often associated with diarrhea
ICD-10
A 09., K 59.1
ICD-9
787.91
DiseasesDB
3742
eMedicine
ped/583
MeSH
D003967

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 rarely 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, Montezuma's Revenge (illness), 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 (Na+) transport. This causes both Cl– and HCO3– to follow passively, as well as water. Once in the intestines, the large volume of water dilutes toxins and distends the intestinal walls. This distention triggers the intestines to contract, pushing their contents towards and out of the anal canal.

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 Coeliac 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 of 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.

Infectious diarrhea
Main article: Infectious diarrhea
Infectious diarrhea is diarrhea cased by a microbe such as a bacterium, parasite, or virus.

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
Main article: Irritable Bowel Syndrome
Another possible cause of diarrhea is Irritable Bowel Syndrome (IBS). 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.[1] 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.[2] 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
Ischemic 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 intestine 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 [3]. 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. Alcohol-induced diarrhea is often accompanied by "the follow through" where a feeling that the patient is going to break wind (flatulence) instead becomes an uncontrolled episode of diarrhea.

See also
Constipation
Feces
Drinking water
The Diarrhea Song
Steatorrhea

Footnotes
^ Longstreth GL, Thompson WG, Chey WD, Houghton LA, Mearin F, and Spiller RC. (2006). Functional Bowel Disorders. Gastroenterology 2006; 130:1480–1491
^ Wangen, S. "The Irritable Bowel Syndrome Solution". page 113. 2006; Innate Health Publishing. ISBN 978-0-9768537-8-7. Excerpted with the author's permission at http://www.ibstreatmentcenter.com/
^ Cite error 8; No text given.

External links

Look up diarrhea in Wiktionary, the free dictionary.
Reducing deaths from diarrhoea through oral rehydration therapy. 1: Bull. World Health Organ. 2000;78(10):1246-55.
Travelers' Diarrhea
Rehydration Project

v • d • e Digestive system - Gastroenterology (primarily K20-K93, 530-579)
Esophagus
GERD - Achalasia - Boerhaave syndrome - Zenker's diverticulum - Mallory-Weiss syndrome - Barrett's esophagus
Stomach/duodenum
Peptic (gastric/duodenal) ulcer - Gastritis - Gastroenteritis - Duodenitis - Dyspepsia - Pyloric stenosis - Achlorhydria - Gastroparesis - Gastroptosis - Portal hypertensive gastropathy
Hernia
Inguinal (Indirect, Direct) - Femoral - Umbilical - Incisional - Diaphragmatic - Hiatus
Noninfective enteritis and colitis
IBD (Crohn's, Ulcerative colitis) - noninfective gastroenteritis
Other intestinal
vascular (Abdominal angina, Mesenteric ischemia, Ischemic colitis, Angiodysplasia) - Ileus/Bowel obstruction (Intussusception, Volvulus) - Diverticulitis/Diverticulosis - IBSother functional intestinal disorders (Constipation, Diarrhea, Megacolon/Toxic megacolon, Proctalgia fugax) - Anal fissure/Anal fistula - Anal abscess - Rectal prolapse - Proctitis (Radiation proctitis)
Liver/hepatitis
Alcoholic liver disease - Liver failure (Acute liver failure) - Cirrhosis - PBC - NASH - Fatty liver - Peliosis hepatis - Portal hypertension - Hepatorenal syndrome
Accessory digestive
Gallbladder (Gallstones, Choledocholithiasis, Cholecystitis, Cholesterolosis, Rokitansky-Aschoff sinuses)
Biliary tree (Cholangitis, Cholestasis/Mirizzi's syndrome, PSC, Biliary fistula, Ascending cholangitis)Pancreas (Acute pancreatitis, Chronic pancreatitis, Pancreatic pseudocyst, Hereditary pancreatitis)
Other/general
Appendicitis - Peritonitis (Spontaneous bacterial peritonitis)
Malabsorption (celiac, Tropical sprue, Blind loop syndrome, Whipple's)
postprocedural: Gastric dumping syndrome - Postcholecystectomy syndromebleeding: Hematemesis - Melena - Gastrointestinal bleeding (Upper, Lower)
See also congenital

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