Dark and Tarry Stool: What to Know

Tarry stool is often black, shiny, sticky, and unusually difficult to wipe away. Blood that has travelled through the stomach or small intestine can turn this colour. Causes can include gastritis, a peptic ulcer, or irritation associated with Helicobacter Pylori Infection. Iron tablets, bismuth-containing products, and some dark foods can also change stool colour, but they do not explain every black stool. Look for context: abdominal pain, nausea, vomiting, reduced appetite, paleness, tiredness, or breathlessness can accompany digestive blood loss.

Contact a medical service promptly if the stool is genuinely tarry or this is a new change. Record when it began, how often it has happened, and whether you have taken iron, bismuth, aspirin, anti-inflammatory pain medicines, or blood thinners. Do not stop a prescribed medicine without advice, and avoid taking extra anti-inflammatory pain medicine while waiting for guidance. A clinician may ask for an examination, blood tests, stool assessment, or other tests.

Go to urgent care for repeated tarry stools, vomiting blood or material resembling coffee grounds, fainting, confusion, marked weakness, severe abdominal pain, rapid breathing, or cold clammy skin. Even without these features, arrange prompt assessment because digestive bleeding can be present before symptoms become dramatic. Information about Gastritis, Peptic Ulcer, and Helicobacter Pylori Infection may help you prepare for the discussion.

Could this be bleeding or a medicine-related colour change? Which medicines should I pause or avoid? Do I need blood tests or a test to look for an ulcer or Helicobacter pylori?