Does Helicobacter pylori infection cause black stools?

Helicobacter pylori can inflame the stomach lining and contribute to an ulcer. Blood exposed to digestive juices may make stools black, sticky, or tar-like, sometimes with an unusually strong smell. Black stool can also have other explanations, including certain foods or iron medicine, but a new tarry appearance should be treated seriously until bleeding has been assessed.

Contact a medical service promptly for new black or tarry stools, particularly if you also have upper abdominal pain, weakness, nausea, or dizziness. Avoid taking anti-inflammatory painkillers unless a clinician has advised them, because they can irritate the stomach. Do not self-treat with antibiotics; testing and a tailored prescription are needed.

Call emergency services for black stools with fainting, confusion, severe weakness, rapid breathing, vomiting blood, or severe abdominal pain. These features may signal significant digestive bleeding. Even without those signs, arrange urgent assessment because a clinician may need to check blood loss, review medicines, and investigate the stomach.

Ask whether the stool appearance suggests bleeding, which medicines or supplements could be contributing, whether Helicobacter pylori testing is needed, and how treatment and follow-up will be arranged.