Rectal bleeding is a common symptom with several possible causes, ranging from haemorrhoids to conditions that need closer investigation. It’s understandable to want to assume the least serious explanation, but a proper assessment is the only way to know for certain and most causes turn out to be very treatable.
What causes rectal bleeding?
Haemorrhoids
The most common cause, typically bright red blood on the paper or in the pan.
Anal fissure
Often bleeding with sharp pain during a bowel movement.
Diverticular disease
Can cause sudden, sometimes heavier bleeding.
Bowel polyps
Usually cause no other symptoms besides bleeding.
Inflammatory bowel disease
Bleeding often alongside a change in bowel habit.
Bowel cancer
Less common, but an important cause to rule out, particularly with other symptoms.
When to seek assessment promptly
- Bleeding that’s new, especially if you’re over 50
- Bleeding alongside a change in bowel habit
- Bleeding with abdominal pain, weight loss, or unexplained tiredness
- Bleeding that persists despite treating suspected haemorrhoids
- A family history of bowel cancer or polyps
How it is investigated
Assessment usually starts with a straightforward examination in clinic, which identifies the cause in many cases without further tests. If needed, flexible sigmoidoscopy or full colonoscopy can be arranged promptly to get a clear answer, with any findings, such as haemorrhoids, a fissure, or polyps, treated or managed directly.
Heavy or ongoing bleeding, bleeding with dizziness or fainting, or bleeding alongside severe abdominal pain needs urgent medical attention, don't wait for a routine appointment.