Bananas and milk can usually be eaten together. There is usually no reaction between bananas and milk. Bananas are rich in potassium ions (about 358mg of potassium per 100g) and vitamins. Milk is rich in protein (3-4g of protein per 100ml) and calcium (105mg of calcium per 100ml), so the combination of banana and milk can better replenish the nutrients in the body. There is no chemical reaction between banana and milk that can produce harmful substances. For diarrhea patients are not recommended to eat bananas, bananas can stimulate the gastrointestinal tract peristalsis, leading to diarrhea symptoms worsen. For patients with constipation, banana intake can be increased moderately. For patients with hyperkalemia, it is not recommended to eat too many bananas, because bananas are rich in potassium ions. Milk should not be ingested by those who are allergic to milk. In addition, bananas and milk should not be ingested in large quantities at one time, so as not to cause digestive burden.