What should you know about black stool and black vomit?

Black stool may be sticky, tar-like, and unusually strong-smelling when blood has been digested as it moves through the stomach and bowel. Black vomit may look like wet coffee grounds because blood has spent time in the stomach. Irritation of the stomach lining, a peptic ulcer, or Helicobacter pylori infection can be associated with upper digestive bleeding. Gastritis is another possible cause. The appearance alone cannot identify the source, and food or medicines can also darken stool, so the combination with vomiting should not be dismissed.

Arrange urgent medical care and describe the colour, texture, and timing of the stool or vomit. Tell the clinician about abdominal pain, dizziness, faintness, medicines, and recent food or drink. Do not take anti-inflammatory pain medicines unless a clinician tells you to, and do not drive if you feel faint. Keep a list of medicines and, if practical, a photograph can help describe the appearance without delaying care.

Call emergency services or go to an emergency department immediately if vomiting continues, you feel faint or confused, your skin is cold or clammy, you have severe abdominal pain, or you cannot keep fluids down. Black vomit or tarry stool with weakness can reflect significant blood loss. Even if you feel well, new black stool without an obvious harmless explanation deserves prompt clinical advice.

Ask what might be causing the bleeding, whether your medicines could contribute, which tests are needed, and which symptoms mean you should return immediately. You can also ask whether gastritis, Helicobacter pylori infection, or peptic ulcer disease needs assessment.