Upset stomach with black stool

Stool that is truly black, sticky or tar-like may contain digested blood from the stomach or upper intestine. Gastritis, a Peptic Ulcer or Helicobacter Pylori Infection can be associated with this pattern, but stool colour alone cannot identify the cause. Iron products, bismuth-containing medicines and some dark foods can also change stool colour. A clinician may need to distinguish these explanations by asking about medicines, appearance and other symptoms.

Do not ignore repeated black or tarry stools. Contact a clinician promptly and describe the colour, texture, timing and any medicines or supplements you take. Avoid taking anti-inflammatory painkillers unless a clinician has specifically advised them, as they can irritate the stomach. Do not stop prescribed medicines without advice. If you feel faint, lie down safely while arranging help and do not drive yourself.

Seek emergency care now for black stools with vomiting blood or coffee-ground material, fainting, severe weakness, confusion, rapid breathing, severe abdominal pain or cold clammy skin. Urgent assessment is also needed when stools remain black or symptoms are worsening. A healthcare team may check circulation, blood tests and the digestive tract to find and treat bleeding.

Could a medicine or supplement explain the colour, or could this be bleeding? Do I need urgent tests? Which pain medicines should I avoid, and what symptoms mean I should return immediately?