Why does Helicobacter pylori infection cause black stools?

Helicobacter pylori can inflame and weaken the lining of the stomach or the first part of the small bowel. If an ulcer there bleeds, digestive processes alter the blood before it leaves the body, making stool look black, sticky, or tar-like. Black Stools is a common presentation of Helicobacter Pylori Infection.

Not every dark stool is caused by bleeding. Iron supplements, bismuth-containing medicines, and some foods can darken stool. However, a newly black, tarry stool should be assessed urgently because gastrointestinal bleeding has other possible causes as well.

Seek urgent medical assessment for black or tarry stools. Be ready to describe when the change started, whether the stool is sticky or unusually smelly, and whether you have abdominal pain, vomiting, dizziness, or weakness. Take a list of your medicines, especially aspirin, ibuprofen, naproxen, anticoagulants, or iron products.

Avoid taking additional anti-inflammatory pain medicines unless a clinician advises you to do so. Do not rely on home remedies to manage a possible internal bleed.

Call emergency services immediately if black stools occur with fainting, severe weakness, breathlessness, confusion, chest pain, severe abdominal pain, vomiting blood, or vomit resembling coffee grounds. These may indicate significant bleeding and need rapid treatment.

Ask whether the stool appearance could be bleeding, which tests are needed, and whether your medicines could be contributing. If Helicobacter pylori is found, ask how treatment will be checked after it is finished.