What should you know about dark green black stool in adults?

Green-black stool may follow leafy foods, dark food colouring, iron, or bismuth-containing products. Faster movement through the bowel can leave bile looking green. These explanations are more reassuring when the change is brief and the stool is otherwise formed without illness symptoms.

A truly black, sticky, tar-like stool can contain digested blood from the upper digestive tract. Gastritis, Helicobacter pylori infection, and peptic ulcer are examples of issues a clinician may investigate. The appearance is a warning sign, not proof of one particular condition.

Write down recent meals, supplements, over-the-counter products, and medicines. Note the stool’s texture, smell, frequency, and any abdominal symptoms. Do not stop a prescribed medicine without professional guidance.

Contact a clinician if the stool stays black, returns without an obvious trigger, or occurs with indigestion, nausea, abdominal discomfort, or unusual tiredness. A medical review may include examination and tests for anaemia or blood in the stool.

Seek emergency care for black tarry stool accompanied by fainting, dizziness, severe weakness, breathlessness, vomiting blood, severe abdominal pain, or a racing heartbeat. Do not wait for another bowel movement when these signs suggest significant blood loss.

Ask whether iron, food, or medicine could explain the colour and whether digestive bleeding should be excluded. Share any history of ulcers or gastritis, stomach symptoms, alcohol use, pain-relieving medicines, and changes in energy or bowel pattern.