Milk and bananas together do not cause diarrhea, on the contrary, milk and bananas together as breakfast is a very healthy combination. If you have occasional bloating and diarrhea, it's probably due to lactose intolerance caused by the lactose in milk, and has nothing to do with bananas. There is also no scientific basis for many of the claims circulating on the internet that you can't eat with milk. As long as the two are normal, clean foods, mixing them together will not cause food poisoning. On the contrary, diversified dietary structure, balanced access to nutrition is more conducive to health.