Bland food is good. Rice, apples, bread and cheese (unless you have a lactose or casein intolerance in which case avoid dairy). Walnuts and other astringent and drying foods are good. Avoid coffee and tea and chocolate and alcohol.
Charcoal can help with the runs. Activated charcoal is best but you can used burnt wood as long as you only use the black stuff. The white powder is toxic.
Do you think you have an infection or do you have a chronic health problem like irritable bowel or inflammatory bowel conditions?