The black color of stools after taking Elavil is mostly normal, as Elavil contains iron, which is not fully absorbed and then excreted, causing black stool color. If you have black stools three days before taking Elavil or three days after stopping taking Elavil, you need to exclude the possibility of bleeding in the stomach and intestines, and you need to take the stools for a routine examination plus an occult blood test to make it clear. Positive occult blood test, need to further ask the patient whether there is abdominal pain, pain in the region, and then targeted to do e-gastroscopy and e-colonoscopy to clarify. The common diseases that cause bleeding in the stomach and intestines are gastric and duodenal ulcers, as well as ulcerative colitis.