Hello I appreciate your concern At the outset I would like to know whether you have lactose intolerance, if it is there than definitely you doctor is right you should avoid milk and diary products If it s not there than there is no meaning to avoid curd and banana both In fact both are beneficial and helpful in diarrhoea I would like further information to help you better frequency and consistency of stools Are you having abdominal pain and vomiting? You may need a course of antibiotics under supervision of your doctor Have probiotics which will strengthen the useful germs in intestine Hope this answers your question follow up questions are most welcome wish you good health best wishes