Causes of Black Vomit and Stool

Black vomit or stool can result from digested blood in the upper digestive tract, although some foods, supplements, or medicines can also darken bowel movements. Vomit may look like coffee grounds, while bleeding-related stool is often black, sticky, and tar-like. Because bleeding can worsen without much warning, black vomit or tarry stool should be assessed urgently, especially when it occurs with weakness, dizziness, fainting, abdominal pain, or a fast heartbeat.

Bleeding from the oesophagus, stomach, or first part of the small intestine can be partially digested as it moves through the body, creating a dark appearance. Possible causes include gastritis, a peptic ulcer, irritation after repeated vomiting, or infection with Helicobacter pylori. Medicines that irritate the stomach or affect clotting can increase concern. Dark stool can also follow iron supplements, bismuth-containing stomach remedies, or strongly coloured foods, but these explanations should not be assumed when the stool is tarry or symptoms are present.

If you have black vomit or tarry stool, contact urgent medical services or go to an emergency department for assessment. Do not drive yourself if you feel faint or weak. Avoid alcohol and do not take aspirin, ibuprofen, or other anti-inflammatory painkillers unless a clinician has specifically told you to do so. Keep a list of your medicines, including blood thinners and supplements, and if possible describe or photograph the vomit or stool for the healthcare team.

Seek emergency help immediately for vomiting blood or coffee-ground material, repeated black stools, fainting, confusion, severe or persistent abdominal pain, breathlessness, cold clammy skin, marked weakness, or a racing heartbeat. These signs can accompany significant blood loss. Children, older adults, pregnant people, and anyone taking a blood thinner should seek advice promptly even if the amount seems small. Do not wait for the colour to return to normal before getting help.

Ask what part of the digestive tract may be bleeding, whether your medicines could contribute, and whether testing is needed to look for gastritis, a peptic ulcer, or Helicobacter pylori. Tell the clinician when the colour change began, whether the stool was sticky or tar-like, what the vomit looked like, and whether you have pain, dizziness, or changes in your usual bowel pattern.