Hi. Thanks for your query. Noted the history about your 10 month old daughter and understood your concerns. Black stool are indicative of bleeding somewhere in the intestinal tract and is very difficult to locate in a small child. Since you are not giving any iron syrup the cause is most probably bleeding. Stool tests for occult blood needs to be done and blood counts repeated to see whether there is fall in hemoglobin, also needed is to do coagulation studies and platelet count. If anything specific is found one should get a proper treatment. If there is no blood in the stool tests then the probable reason can be that the stool has bacterial infection by dark pigment producing bacteria and many a times a dark stool is mistaken for malena. Get a consultation of a Pediatric surgeon as pediatric upper GI Endoscopy and colonoscopy may be available and be done to rule out any problems giving black stools.