Lactobacillus

Foods to eat when you have diarrhea are:
- bananas have pectin which is a soluble fiber and bananas also have increased amount of potassium which replaces an important electrolyte.
- rice, white bread (dry toast), crackers, and mashed plain potatoes because they are low in fiber and digested without difficulty in the upper GI tract.
- drink lots of fluids including clear liquids such as water, apple juice, sports drinks, and teas such as peppermint and chamomile.
- steamed white meat of the chicken.
- cooked apples are a source of pectin, sugar, and nutrients.
- dried blueberries which are a source of soluble fiber and antioxidant, they contain tannins which may decrease loss of fluids.

Foods to avoid when you have diarrhea are:
- avoid dairy and milk products with the exception of yogurt with live cultures of Lactobacillus acidophilus and Bifidobacterium bifidum
- caffeinated beverages.
- sugar free foods and diet sodas.
- fatty foods.
- gas producing foods, such as beans, broccoli, or cauliflower.
- dairy products such as ice cream and cheese.
- alcohol. Changing your diet can reduce the comfort of diarrhea.

Avoid foods that irritate the Gastrointestinal system, such as greasy, spicy, or fried foods.

Also avoiding milk and other dairy products may help. Diarrhea can get rid of the enzyme used to break down dairy products called lactase making dairy difficult to digest.

http://www.chemotherapy.com/side_effects/other_side_effects/diarrhea.html has a few more tips on how to handle diarrhea.