Hi. Thanks for your query. Noted the history and understood your concerns. The black stool usually indicate bleeding into the gastrointestinal tract, the commonest cause can be gastric or duodenal ulcer. Hence the first thing to do is always insist for an upper GI Endoscopy, Colonoscopy and tests of blood for any bleeding disorders, any medications that can cause bleeding disorders and also to stop iron as medications or stop foods rich in iron. The bleeding per-rectum as you have explained can be due to many a factors like fissure in ano or piles or polyp. Per-rectal examination, ano-proctoscopy can help to get a proper diagnosis. Clinical evaluation by a Gastroenterologist and investigations can get you the best possible diagnosis and a plan for proper management.