Hi. Thanks for your query. Noted the history and understood your concerns. Pint of sour milk and banana as a shake can cause intolerance or can cause symptoms of food poisoning hence you have got cramps and diarrhea. I would advise you the following: Get the stool and blood sample checked. A course of an antibiotic may be of help. Take activated charcoal tablets and also pre and probiotics. If there is no nausea or vomiting take plenty of oral fluids and electrolyte solution to maintain the hydration and electrolyte balance. Avoid such preparations in future.