What's acute diarrhea?

The most common organisms found are Campylobacter (an organism of animal or chicken origin), salmonella (also often of animal origin), Cryptosporidiosis (animal origin), Giardia Lamblia (lives in drinking 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). E 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 is common in children. (Viral diarrhea is probably over-diagnosed by non-doctors). The Norwalk virus is rare. Toxins and food poisoning can cause diarrhea. These include staphylococcal toxin (see Staphylococcus)(often milk products due to an infected wound in workers), and Bacillus cereus (eg rice in Chinese takeaways). Often "food poisoning" is really salmonella infection. Diarrhea is a common side effect of drugs (especially antibiotics). Clostridium difficile infection is potentially serious and is often related to antibiotic use.

Parasites and worms sometime cause diarrhea but often present with weight loss, irritability, rashes or anal itching. The commonest is pinworm (mostly of nuisance value rather than a severe medical illness). Other worms such as hook worm, ascaris and tapeworm are more medically significant and may cause weight loss, anemia, general unwellness and allergic problems. Amoebic dysentery due to Entaeomeba histolytica is an important cause of bloody diarrhea in travelers and also sometimes in western countries which requires appropriate and complete medical treatment.

More information on diarrhea