Diarrhea is usually caused when the fluids within the intestines are not reabsorbed by the gut walls. This leads to loose, watery stools. Watery stools may also result from excessive water secretion from the intestines into the lumen or bowel.
Diarrhea may be acute or chronic. Most cases of diarrhea begin suddenly and usually resolve on their own within a day or two.
Diarrhea lasting for more than two days may be problematic. Diarrhea is called chronic when it lasts for at least four weeks. This is usually due to some underlying functional or systemic disorder.
Diarrhea is a symptom of an underlying infection of the gastrointestinal tract rather than a disease in itself. Gastrointestinal infection may be caused by infections due to:-
Common bacteria that may cause diarrhea include Clostridium difficile (C. difficile), Escherichia coli (E. coli), Salmonella, Campylobacter and Shigella. These may all cause food poisoning and occur due to eating or consuming contaminated food or water. When gastroeneteritis occurs to travellers to developing countries in Africa, Asia, Latin America, and the Caribbean, it is termed Traveller’s diarrhea.
Several viruses may give rise to serious acute episodes of diarrhea. These include norovirus, rotavirus, herpes simplex virus, cytomegalovirus, hepatitis virus etc.
These agents are also notorious is causing diarrhea in children and in some adults. Some of the parasites that may cause diarrhea include Giardia lamblia, Entamoeba histolytica, and Cryptosporidium.
Other causes of short term acute diarrhea include:-
Chronic diarrhea usually lasts over 4 weeks and may be caused by an underlying gastrointestinal or systemic disease. Some of the causes include:-