Hello. Good day. Thanks for writing to HCM. I am Dr Praveen and I will be answering your query today. You need to do a stool routine examination and look for ova and parasites as well. In giardiasis you can have such symptoms which includes post feed loose stools. That can be treated with antibiotics. Sometimes, if you dont respond to an empirical trial of antibiotics you will need to undergo a colonoscopy. It would have been nice to know your age and if your body is normally developed. I mean to ask if there are signs of nutritional deficiencies in which case malabsorbtion syndromes could be likely. Wishing you good health. Please hit thanks and rate this answer if you have found it helpful. Warm regards.