Black slimy stool: what to know

Mucus can make stool look slippery, but black, glossy, sticky material is more concerning for digested blood from the stomach or upper intestine. Gastritis and peptic ulcers are possible sources; Helicobacter pylori infection can contribute to inflammation or ulcer disease. Iron, bismuth, and dark foods can also turn stool black, usually without a tar-like feel. A description of the colour, shine, stickiness, smell, and any associated symptoms helps a clinician judge the urgency.

Seek same-day medical advice for unexplained black slimy stool. Photographing the stool, if practical and private, can help show its appearance. Bring a list of medicines and supplements, including pain relievers and iron. Take small sips of fluid if you are otherwise well, but do not delay care to monitor it. Avoid aspirin or ibuprofen unless prescribed for your specific situation.

Call emergency services for fainting, confusion, severe weakness, rapid heartbeat, pale clammy skin, severe abdominal pain, vomiting blood, or vomit that looks like coffee grounds. Reduced urination may signal dehydration or reduced circulation. Black tar-like stool should be treated as urgent even when pain is absent, because bleeding in the upper digestive tract may not begin with strong discomfort.

Could this be bleeding or mucus with a medicine-related colour change? Should I be checked for an ulcer or Helicobacter pylori infection? Which pain medicines are safer for me? What symptoms require emergency treatment?