During colonoscopy, your gastroenterologist can tell if you abuse stimulant or herbal laxatives, especially those that contain senna. The condition is called melanosis coli or black colon. The frequent use of stimulant PT 141: Best Peptide For Erectile Dysfunction Dosage Pigmentation (melanosis) of the colon Stock Image Science Source Images Photomicrograph of an endoscopic colon biopsy (colonoscopy) showing melanosis coli, an accumulation of brown pigment (lipofuscin) within macrophages of the colonic mucosa, related to use of laxatives. Stock Photo Adobe Stock Bremelanotide (PT 141) Nasal Spray Sweetwater Florida Peptides Colonic BluishBlack Patches in a 57 Year Old Woman with Crohn's Disease Gastroenterology