Rectal Bleeding
Many conditions can cause rectal bleeding, and the blood’s appearance can reveal its source. Bright red blood often points to anorectal conditions such as haemorrhoids, anal fissures, or anal fistulas, showing that the bleeding originates near the rectum or anus.
Darker or older blood mixed with stool usually indicates bleeding higher in the colon, caused by polyps, colon cancer, diverticular disease, or inflammatory bowel disease. Vascular abnormalities in the bowel, such as angiodysplasia, can also trigger bleeding. Black stool, called melaena, signals bleeding from the upper gastrointestinal tract, such as a peptic ulcer.
Most patients with blood in the stool have a benign cause, but you should seek medical attention if you notice bleeding, since some conditions require early diagnosis and treatment.