Hi. Thanks for your query. Noted the history of your child birth, taking lemon water and started with black stool. It is not possible that the lemon water can really cause any black stools. The causes can be: - GI bleed somewhere for which you need investigations. - It is possible that you also taking iron tablets which on conversion give the back color to the stool. I would advise you the following: - Upper GI endoscopy. - Colonoscopy - Capsule endoscopy if both the above endoscopies are normal. - CT scan of the abdomen with intra-venous contrast if required. - Tests of stool and blood. Appropriate treatment as per the findings and final diagnosis. Till then get started on a PPI like Omeprazole, antacid on empty stomach and avoid stress and anxiety.