<<Disclaimer: Verify this information before applying it to your situation.>> I found this excerpt about Celiac & Sprue here - http://www.rehydrate.org/dd/html/dd10.htm - thought it was interesting. Along with the problems in 3rd world countries this panel of International Doctors were the first I've heard mention Celiac Sprue being provocked by Tropical exposure (which really helps put the pieces together for me (as far as probabilities go). Major causes of chronic diarrhoea Dietary causes A component of food grains (particularly wheat) known as gluten can cause small bowel disease (gluten enteropathy or coeliac disease). The mucosal lining of the gut is more severely affected than in tropical malabsorption and the condition can, on rare occasions, be provoked by tropical exposure. The only effective treatment is to completely remove gluten from the diet; there is no response to antibiotics and folic acid. Hypolactasia is a deficiency of the digestive enzyme which splits lactose, the sugar found in milk. Any condition which damages the mucosal lining of the small intestine can produce hypolactasia. It also occurs any time after three or four years of age as an inherited characteristic among a significant range of populations. Chronic diarrhoea results if large amounts of milk are consumed but the absorption of other foods is not affected.