Blood in stool and dark urine: what to know

Bright red blood on tissue or the outside of stool can come from the anus or lower bowel. Maroon stool or black, sticky stool may indicate bleeding further inside the digestive tract. Inflammation, diverticular disease, bowel polyps, and other bowel conditions are possible explanations, but appearance alone cannot identify one.

Dark urine may result from dehydration, concentrated urine, food or medicines, or blood and other substances entering the urine. Brown urine with yellowing of the skin or eyes, pale stools, or marked itching needs medical attention because it can point to a liver or bile-flow problem. Blood in stool does not normally make urine dark.

Contact a clinician promptly and describe the stool and urine separately. Mention pain, diarrhoea, fever, reduced urination, burning when passing urine, back pain, vomiting, recent foods, new medicines, and any history of bowel, kidney, or liver problems.

Drink small amounts of water regularly if you can do so and have not been told to restrict fluids. Do not stop prescribed medicines without advice, but specifically mention blood thinners and anti-inflammatory pain medicines. A clinician may examine you and arrange urine and blood tests, with further bowel assessment if needed.

Use emergency care for heavy or repeated rectal bleeding, black tar-like stool, fainting, severe abdominal or back pain, confusion, very little urine, inability to keep fluids down, or rapidly worsening weakness. Seek urgent assessment for dark brown urine with jaundice, fever, or severe pain.

Ask whether the urine needs testing for blood or concentration, whether the bowel bleeding needs a bowel examination, how your medicines affect risk, and which changes should prompt emergency care.