Bacterial agents were sought by culture, and Giardia , Entamoeba histolytica, and Cryptosporidum were sought by commercial enzyme immunoassay. Viral pathogens were not sought. Mild TD was the passage of 1 to 2 unformed stools in a 24-hour period. Moderate TD was defi ned as passage of 1 to 2 unformed stools together with a symptom or sign of an enteric infection including excessive intestinal gas – related symptoms, abdominal cramps or pain, nausea, vomiting, fever, or dysentery (passage of grossly bloody stools). Classic TD was defined as passage of ≥ 3 unformed stools plus one of the above signs or symptoms of enteric infection.