What does black stool mean?

Notice whether the stool is simply dark brown or truly black, sticky, and tar-like. Iron and bismuth can darken stool without bleeding. Melena has a characteristic tarry appearance and strong odour, although appearance is not enough to diagnose the cause. Gastritis, peptic ulcer, and Helicobacter pylori infection are among the conditions a clinician may consider.

Write down when the colour changed and whether it happened once or repeatedly. Make a list of medicines, supplements, and recent foods; include iron, bismuth products, aspirin, and anti-inflammatory pain relievers. Arrange medical advice for unexplained black stool rather than trying to diagnose it from colour alone. Do not use someone else’s medicine.

Get emergency help if black stool occurs with faintness, dizziness, marked weakness, rapid breathing, severe abdominal pain, vomiting blood, or coffee-ground vomit. Seek prompt care when the stool is tarry, keeps recurring, or appears with a history of ulcer disease or blood-thinning treatment.

Ask whether a medicine or supplement could explain the colour, whether you need examination or testing, and whether symptoms suggest gastritis, a peptic ulcer, or Helicobacter pylori infection. Ask what changes require emergency care.