Black stool and fever: what to know

A fever suggests the body is responding to infection or inflammation, but it does not identify the cause of black stool. Melaena is typically dark, sticky, and strong-smelling when blood has been digested in the upper digestive tract. Iron, bismuth remedies, and dark foods can also change stool color without bleeding. Fever with diarrhea, chills, vomiting, rash, cough, or painful skin may point toward an illness elsewhere or a gastrointestinal infection. The conditions linked from this page include Acute Bronchitis, Bronchiolitis, Brucellosis, Cellulitis, Chickenpox, Common Cold, COVID-19, and Croup; a clinician will use the full symptom pattern rather than fever alone.

Check your temperature and note when the stool changed, how it looks, and whether fever is rising or settling. Drink small, regular amounts of fluid if you can keep them down. Do not use leftover antibiotics, and avoid ibuprofen or aspirin until a clinician has considered possible bleeding. Seek same-day medical advice for unexplained black stool with fever, especially if you are taking a blood thinner or feel increasingly unwell.

Go to emergency care for fainting, confusion, severe weakness, vomiting blood, coffee-ground vomit, severe abdominal pain, breathing difficulty, a stiff neck, or inability to keep fluids down. Urgent help is also needed for signs of dehydration such as very little urine, a dry mouth, or worsening dizziness. Babies, frail adults, and people with reduced immunity need a lower threshold for assessment.

Ask whether the stool could be melaena, whether infection testing is needed, and whether any current medicine should be stopped or changed. Mention recent travel, sick contacts, new foods, antibiotics, iron or bismuth, blood thinners, and any rash or respiratory symptoms. Ask how to monitor fever and which changes require emergency care.