hello thank you for trusting HCM dear in old age people with diarrhoea milk is not good for health. old age people not contain the enzyme lactase to digest it cause diarrhoea. use yoghurt and probiotic tablet s.cooked rice juice,ors sachets,plenty of oral fluids.etc avoid spicy food and caffeine. use metronidazole and Ciprofloxacin for diarrhoea.if symptoms not improved please consult with your doctor he will examine and treat you accordingly.also you can use cooked cereal like cream of wheat or farina soda crackers,applesauce and apple juice etc.. I think I answered to your question if you have more questions feel free to ask. take care