Causes of black stool during pregnancy

Iron supplements commonly darken stool, and some foods or products can change its colour. Bleeding higher in the digestive tract can produce stool that is black, sticky, and tar-like, sometimes with a strong smell. Gastritis and peptic ulcer disease are possible sources of upper digestive bleeding. Helicobacter pylori infection can contribute to stomach or ulcer irritation and requires medical assessment. Colour alone cannot reliably separate harmless darkening from melaena, so describe the texture, smell, frequency, and any related symptoms.

Note every supplement, medicine, and food that may affect colour, and do not stop prescribed pregnancy treatment without advice. Contact your maternity team or clinician to discuss black stool, especially if it is tarry or the cause is unclear. They can review your symptoms, medicines, pregnancy stage, and need for examination or testing.

Get urgent medical help for black tarry stool with dizziness, faintness, weakness, fast heartbeat, shortness of breath, abdominal pain, repeated vomiting, or vomit that looks like coffee grounds. Seek immediate care for visible blood or heavy bleeding. Pregnancy does not make these warning signs safe to watch at home.

Ask whether your iron product could explain the colour, which features suggest bleeding, and where to go if the stool becomes tarry or you feel faint.