diarrhea

http://en.wikipedia.org/wiki/Diarrhea

Diarrhea (AmE) (or diarrhoea) (BrE) (from the Greek διάρροια, δια dia
"through" + ρέω rheo "flow" meaning "flowing through"[2]) is the
condition of having three or more loose or liquid bowel movements per
day.[3] It is a common cause of death in developing countries and the
second most common cause of infant deaths worldwide. The loss of
fluids through diarrhea can cause dehydration and electrolyte
disturbances such as potassium deficiency or other salt imbalances.

In 2009 diarrhea was estimated to have caused 1.1 million deaths in
people aged 5 and over[4] and 1.5 million deaths in children under the
age of 5.[1] Oral rehydration solutions (ORS) with modest amounts of
salts and zinc tablets are the treatment of choice and have been
estimated to have saved 50 million children in the past 25 years.[1]
In cases where ORS is not available, homemade solutions are often
used.

Definition

Diarrhea is defined by the World Health Organization as having three
or more loose or liquid stools per day, or as having more stools than
is normal for that person.[3]

Secretory

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 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. In this type of diarrhea
intestinal fluid secretion is isotonic with plasma even during
fasting.[5] It continues even when there is no oral food intake.

Osmotic

Osmotic diarrhea occurs when too much water is drawn into the bowels.
If a person drinks solutions with excessive sugar or excessive salt,
these can draw water from the body into the bowel and cause osmotic
diarrhea.[6] Osmotic diarrhea can also be the result of maldigestion
(e.g., pancreatic disease or Coeliac disease), in which the nutrients
are left in the lumen to pull in water. Or it can be caused by osmotic
laxatives (which work to alleviate constipation by drawing water into
the bowels). In healthy individuals, too much magnesium or vitamin C
or undigested lactose can produce osmotic diarrhea and distention of
the bowel. A person who has lactose intolerance can have difficulty
absorbing lactose after an extraordinarily high intake of dairy
products. In persons who have fructose malabsorption, excess fructose
intake can also cause diarrhea. High-fructose foods that also have a
high glucose content are more absorbable and less likely to cause
diarrhea. Sugar alcohols such as sorbitol (often found in sugar-free
foods) are difficult for the body to absorb and, in large amounts, may
lead to osmotic diarrhea.[5] In most of these cases, osmotic diarrhea
stops when offending agent (e.g. milk, sorbitol) is stopped.

Exudative

Exudative diarrhea occurs with the presence of blood and pus in the
stool. This occurs with inflammatory bowel diseases, such as Crohn's
disease or ulcerative colitis, and other severe infections such as E.
coli or other forms of food poisoning.[5]

Motility-related

Motility-related diarrhea is caused by the rapid movement of food
through the intestines (hypermotility). If the food moves too quickly
through the gastrointestinal tract, there is not enough time for
sufficient nutrients and water to be absorbed. This can be due to a
vagotomy or diabetic neuropathy, or a complication of
menstruation[citation needed]. Hyperthyroidism can produce
hypermotility and lead to pseudodiarrhea and occasionally real
diarrhea. Diarrhea can be treated with antimotility agents (such as
loperamide). Hypermotility can be observed in people who have had
portions of their bowel removed, allowing less total time for
absorption of nutrients.

Inflammatory

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 diseases. It can also be caused by tuberculosis,
colon cancer, and enteritis.[citation needed]

Dysentery

Generally, if there is blood visible in the stools, it is not
diarrhea, but dysentery. The blood is trace of an invasion of bowel
tissue. Dysentery is a symptom of, among others, Shigella, Entamoeba
histolytica, and Salmonella.

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