Abdominal pain and dark stool: when to get help

Some medicines, supplements and foods can darken stool, but colour alone cannot safely distinguish them from digested blood. The combination of abdominal pain and a tar-like appearance should be assessed without waiting for another bowel movement.

Bleeding higher in the digestive tract can turn stool black and give it a sticky, tar-like consistency. Stomach inflammation or an ulcer may also cause upper abdominal discomfort, nausea or vomiting. Gastritis can present with upper abdominal pain, and bleeding symptoms need urgent assessment regardless of the suspected cause.

Iron supplements and some medicines containing bismuth can make stool dark without bleeding. Certain deeply coloured foods may also change its appearance. Tell the clinician what you have taken and eaten, but do not use that history to dismiss tar-like stool when pain, weakness, dizziness or vomiting is present.

Seek urgent medical assessment today if the stool is black and tar-like and you have abdominal pain. If you feel faint, confused, very weak, short of breath, clammy or unable to stand safely, call emergency services and do not drive yourself.

Bring a current medicine and supplement list, including pain relievers and any medicine that affects blood clotting. Note when the stool changed, its consistency, the pain location and whether you vomited. Do not take an extra dose of an anti-inflammatory pain medicine for the abdominal pain while bleeding is a concern; a clinician or pharmacist can advise about your regular medicines.

Call emergency services for vomiting blood or material resembling coffee grounds, fainting, confusion, severe or rapidly worsening abdominal pain, breathing difficulty, a racing heartbeat with marked weakness, or signs of shock such as cold clammy skin. These symptoms can accompany significant bleeding or another acute abdominal problem.

Even without those signs, black tar-like stool plus abdominal pain warrants urgent same-day assessment. Dark brown stool that is not sticky or tar-like may be less concerning, but contact a clinician if the colour is unexplained, persists, or is accompanied by pain, fatigue, dizziness, vomiting or visible blood.

Explain whether the stool was jet black, sticky or unusually strong-smelling, and describe any red blood or vomit. Ask whether your medicines could contribute to bleeding or colour change, what tests are needed to locate the cause, and which regular medicines you should take while being assessed.