Black stool and stomach pain: what should you know?

Stool that is truly black, sticky, and tar-like may contain digested blood from the stomach or upper intestine. Stomach irritation, gastritis, or an ulcer can sometimes cause this pattern and may also cause burning or aching pain. Black stool is not automatically a sign of a serious disease: iron tablets, bismuth-containing stomach remedies, liquorice, and very dark foods may make stool look dark. These causes do not usually create a tar-like texture or make you faint.

The location and character of pain matter. Pain high in the abdomen may accompany stomach irritation, while cramping with diarrhoea can occur with gastroenteritis or food poisoning. Other digestive conditions, including Crohn's Disease, can cause abdominal pain and altered bowel habits, but stool colour alone cannot identify the cause.

Look at the stool in good light and note whether it is sticky or tarry, how often it has occurred, and when the pain began. Make a list of recent medicines and supplements, especially iron, bismuth, aspirin, ibuprofen, or other anti-inflammatory painkillers. Do not take extra anti-inflammatory painkillers to manage the pain, and do not stop a prescribed medicine without medical advice. Arrange prompt clinical advice if the colour change is unexplained, keeps returning, or occurs with ongoing pain.

Drink small amounts of fluid if you can keep them down. Avoid alcohol until the cause is clear. A clinician may ask about your symptoms, examine your abdomen, review medicines, and decide whether blood tests or other investigations are appropriate.

Seek emergency help if black tarry stool is accompanied by vomiting blood or material that looks like coffee grounds, severe or worsening abdominal pain, fainting, confusion, marked weakness, breathlessness, a fast heartbeat, or cold clammy skin. These symptoms can signal significant bleeding or another urgent abdominal problem.

Get same-day medical advice for repeated black stools, unexplained black stool, dizziness, or pain that does not settle. Do not drive yourself if you feel faint or weak. Tell the clinician about pregnancy, previous ulcers or digestive bleeding, and every medicine or supplement you take.

Ask: Could my medicines or supplements explain the colour? Does the stool look like digested blood? What might be causing the pain, and which warning signs should prompt emergency help? Bring the product names, doses, and a description or photo of the stool if appropriate.