Does she take milk and is she having these symptoms after consuming milk? As you say that her test results are all normal and there is no serious medical issue, just check what she has been eating/drinking of late which might be causing problems. If she is having difficulty in digesting milk, then she must be lactose intolerant. Generally people in old age have a hard time digesting milk and present with symptoms such as diarrhoea, constipation, gas, bloating sensation in stomach and abdominal cramping. Try to feed her small quantites of food and liquid containing glucose at regular short intervals to ensure she doesn t become weak. Omit any foods which might be causing discomfort and give only simple, well-cooked, easily digestible foods. Avoid fibre rich foods and give cabohydrates to meet her energy needs like starchy foods such as boiled rice,potatoes, bread. Avoid gas forming foods like raw onions, cabbage, beans etc. If non-vegetarian, you can give mutton, chicken, eggs and fish. If she is not accepting solid foods, you can prepare thick soups both veg and non-veg, add corn starch for thickening, some butter or cream for energy. Give her bananas, curd, fresh fruit juices with added sugar. Hope this will help you in feeding your mother well.