Crohn's Disease & Ulcerative Colitis Support Group
Crohn's disease is a systemic inflammatory bowel disease (IBD) of unknown cause, that results in chronic inflammation of the intestinal tract. It can affect the entire gastrointestinal tract from mouth to anus, and can also cause complications outside of the gastrointestinal tract. There is no known medical or surgical cure for Crohn's disease, but there are many medical...

If there's any change in your diet or meds, that can change your poop color too. If you're not eating a lot of fiber or drinking enough water, not only can that make your poop dark (no fiber means it sits in your colon longer causing it to be darker), but that can be the reason it's sinking.