What should you know about black floating poop?

Stool can look dark after certain foods or products containing iron or bismuth. Floating may follow extra gas or changes in digestion and does not, by itself, identify a disease. Black stool that is sticky, tar-like, unusually strong-smelling, or repeatedly present is more concerning for digested blood, sometimes called melaena.

Bleeding can occur with irritation of the stomach lining, known as [Gastritis](/conditions/gastritis/), or with a [Peptic Ulcer](/conditions/peptic-ulcer/). [Helicobacter Pylori Infection](/conditions/helicobacter-pylori-infection/) can contribute to stomach inflammation and ulcer disease.

Notice whether the stool is truly black rather than dark brown, and record how often it occurs. Make a list of iron, bismuth, anti-inflammatory pain medicines, blood thinners, supplements, and recent foods. Do not stop prescribed treatment without advice, but contact a clinician promptly if the colour is unexplained or persists.

Keep hydrated and avoid taking extra anti-inflammatory pain medicine until a clinician has advised you, especially if bleeding is possible. A clinician may ask about abdominal pain, nausea, vomiting, previous ulcers, and changes in bowel habits.

Seek emergency care for black tarry stool with dizziness, fainting, weakness, pale or clammy skin, rapid heartbeat, severe abdominal pain, or vomiting blood or material that resembles coffee grounds. Prompt assessment is needed for repeated black stools, even when pain is mild, because digestive bleeding may not cause strong symptoms at first.

Ask whether the appearance could be caused by a food or medicine, whether you need testing for bleeding or Helicobacter pylori, and which medicines to avoid. Tell the clinician when it started and whether you have pain, vomiting, dizziness, or a history of ulcers.