Anemia and black stool

Blood exposed to digestive juices can become dark, sticky, and unusually strong-smelling before it leaves the body. Ongoing blood loss can reduce red blood cells and iron stores. However, iron tablets, bismuth-containing medicine, and some dark foods can also change stool colour without bleeding.

Bleeding can arise from irritation, inflammation, or an ulcer in the oesophagus, stomach, or upper small intestine. Gastritis, a peptic ulcer, and Helicobacter pylori infection are among the conditions a clinician may consider, but the appearance of stool cannot identify the source on its own.

Report whether the stool is sticky or tar-like, when the change began, and whether you have abdominal pain, vomiting, weakness, dizziness, or breathlessness. Mention iron, bismuth, anti-inflammatory painkillers, blood-thinning medicines, and supplements.

Contact a healthcare service promptly for new black, tar-like stool, especially if anemia is known or suspected. A clinician may check your pulse and blood pressure, examine your abdomen, order blood tests, and decide whether examination of the digestive tract is needed.

Do not assume the colour is harmless because you take iron. Keep a list of medicines and note the stool appearance, but do not stop prescribed blood thinners or other essential treatment unless the clinician managing you gives specific instructions.

Go to an emergency department or call local emergency services if black stool occurs with fainting, severe weakness, confusion, chest pain, difficulty breathing, a rapid heartbeat, cold clammy skin, vomiting blood, or vomit that resembles coffee grounds.

These signs may reflect substantial blood loss or impaired circulation. Avoid driving yourself if you are dizzy or faint, and have someone stay with you while help is arranged.

Ask whether the stool appearance suggests bleeding, whether any medicine raises concern, and which tests can locate the source. Clarify how the anemia will be treated, what changes should trigger emergency care, and how follow-up blood results will be checked.