Hi. Thanks for your query. Noted the history and understood the concerns. Your short history is indicating that you have been prescribed Doxycycline for intestinal infection yet you have a problem and also have been prescribed IBSet thinking this to be IBS possibly. You are having loose stools only once in a day in the morning indicating that there is no proper absorption of water from colon or may be intolerance to something or less pancreatic activity and so on. Since you have already done a stool test showing only a few pus cells and so on, I would advise you the following in such a situation: Get an opinion of a Doctor again. Get review stool test and if the infection is present a course of an antibiotic., metronidazole should helps you. Probiotics, bananas, yogurt/curds, activated charcoal may help you further. Also watch for the foods and beverages that cause more problems and eliminate these from diet. Relevant blood tests, ultrasonography sometimes help for diagnosis and management. Use boiled and cooled water, homemade fresh foods only.