Brief Answer: Oral Iron therapy could be the commonest cause Detailed Answer: Hi Welcome to Healthcare-Magic Greetings of the day Dear Ms, It would be very helpful if you could clarify you had lumpectomy at which site. Causes of black stools could be the following 1. Oral Iron supplements: Taking oral iron supplementation can cause blackish discolouration of stools. This is one of the commonest cause for blackish discolouration of stools. 2. Upper Gastrointestinal bleeding: Bleeding from either Gastric or duodenal ulcer undergoes hemolysis and causes blackish discolouration of stools. Its likely to be intermittent . Taking antacid and also proton pump inhibitor may be helpful. Also avoid spicy and oily food. If the blackish discoluration persists, I would suggest you to consult your Physician for further clinical evaluation. At any given point if you need any further assistance, will be glad to assist you. Take Care Best Regards Dr T Shobha Deepak MBBS,MD

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