If someone had black poop for a week, then it returned brown for 3 months, then black poop again, what could it be. sorry for the sloppy question?

Be seen: It can be caused by several things, but most concerning would be from internal bleeding. You need to be checked.

Important question!: If your bowel movements have been black - like tar - you may be having bleeding from somewhere in your gastrointestinal tract. Blood turns black as it moves through the system. (i'm not talking dark brown - like people get when they take iron). See your doctor about this; you will likely be referred to a gastroenterologist for a colonoscopy. Don't put this off; it could be life-saving.

Could be dietary: Oreo cookies, iron pills, pepto bismol, (bismuth subsalicylate) stomach ulcers, and other things can turn your stool black. If you, for example, have taken the 1st three by mouth during the given week (sale on cookies, new vitamins, upset stomach), then that would explain the stool color change. If not, then it may be resonable to rule out stomach bleeding from ulcer. I would expect abdominal pain during this time, tho..