Solitary rectal ulcer syndrome: causes and care

The rectum is the last part of the large bowel, where stool waits before it passes out through the anus. In solitary rectal ulcer syndrome the lining of this area becomes inflamed, thickened or ulcerated.

The MSD Manual, a clinicians' reference, notes that the condition is poorly named, since the lesions may be single or multiple and may or may not be ulcerated. They range from simple redness to ulcers to small raised areas, and they are typically found on the front wall of the rectum within about 10 cm of the anal opening.

Because of this variety, doctors often prefer to describe the whole picture rather than a single sore. The ulcer is one visible sign of an underlying problem with how the rectum is being stretched, squeezed or rubbed. That is why the cause matters as much as the ulcer itself.

Symptoms usually develop slowly and revolve around difficult or unsatisfying visits to the toilet. Cleveland Clinic lists rectal bleeding, which is usually bright red, mucus or blood in the stool, straining or opening the bowels too rarely, a frequent urge to go without being able to empty, discomfort around the anus and a feeling of fullness in the pelvis. The MSD Manual adds a sense of incomplete evacuation as a core feature.

Some people have very little. Cleveland Clinic states that up to a quarter of those with the syndrome have no symptoms, so a rectal ulcer is sometimes found by chance during a bowel examination arranged for another reason.

• Bright red blood on the paper, on the stool or in the pan.

• Passing mucus, sometimes with blood.

• Spending long periods on the toilet, or repeated trips with little result.

• Pressure, heaviness or a feeling that something is blocking the passage.

• Pain or discomfort when opening the bowels.

No single cause has been identified. The MSD Manual describes the lesions as arising from reduced blood supply to the lining of the lower rectum after repeated injury. It lists rectal prolapse, a puborectalis muscle that tightens instead of relaxing, chronic constipation and attempts to remove hard stool with the fingers as the usual sources of that injury.

Cleveland Clinic describes a theory that the pelvic floor muscles fail to coordinate when stool needs to pass, so the person pushes against a muscle that is closed. It also names rectal intussusception, in which part of the rectum slides inside the part below it, and bowel incontinence as conditions that often sit alongside the ulcers. In prolapse or intussusception, tissue that would not normally touch is dragged against other tissue each time the person strains.

The practical message is that the ulcer is rarely the starting point. Long-standing constipation and the habit of pushing hard are the usual story, which is why treatment concentrates on the bowel habit.

A clinician will ask about your bowel habits, any straining or manual assistance, and any blood. A rectal examination with a gloved finger is usual. The MSD Manual says diagnosis is typically made from the history together with a flexible sigmoidoscopy, a thin camera examination of the rectum and lower colon, with a biopsy taken sometimes to confirm it.

Cleveland Clinic lists further tests that may look for the cause: a transrectal ultrasound, a defecography study using X-rays or MRI to watch the muscles during a bowel movement, and anorectal manometry to measure how the pelvic floor muscles coordinate. A biopsy shows whether cells are benign. Colonoscopy may be needed to exclude inflammatory bowel disease and bowel cancer.

The NHS page on bleeding from the bottom stresses that bleeding is sometimes a sign of bowel cancer, which is easier to treat when found early, and it lists a GP visit if blood in the stool has lasted 3 weeks. For that reason, new bleeding should be reviewed rather than put down to a rectal ulcer by guesswork.

Treatment depends on the severity of symptoms and on what is driving them. According to Cleveland Clinic, many people with mild to moderate symptoms improve by changing eating and toileting habits so stool is easier to pass, and avoiding straining gives the ulcer time to heal. Its list includes drinking enough water, eating plenty of fibre, not pushing hard, and using a stool softener or bulking laxative on a provider's advice. The MSD Manual likewise describes reassurance and a bowel regimen with bulk laxatives for mild cases.

The NHS constipation page offers practical steps that suit this situation: keep to a regular time and place, do not ignore the urge, rest the feet on a low stool so the knees sit above the hips, and consider more activity. It advises speaking to a pharmacist about a suitable laxative if diet and lifestyle changes are not enough.

Cleveland Clinic says that medicines applied to the rectum, such as a corticosteroid cream or suppository, can reduce inflammation, and that sucralfate and sulfasalazine are prescription medicines used by mouth. These are decisions for a specialist.

If simpler measures do not help, Cleveland Clinic describes biofeedback therapy. This is behavioural training that helps a person recognise when they tighten the muscles used to pass stool and relax them instead, so that straining is reduced. It is usually delivered by a trained physiotherapist or nurse at a pelvic floor or bowel service.

Surgery is not routine. Cleveland Clinic explains that where rectal prolapse or intussusception is causing the ulcers, a rectopexy may be advised to repair the rectum and hold it in position, and that it can be done by keyhole or robotic methods. The MSD Manual says surgery is sometimes needed if rectal prolapse is the cause. The choice is made by a colorectal team after tests show whether prolapse is present.

Cleveland Clinic states that rectal ulcers are benign and do not cause serious long-term medical problems, though they can cause pain and ongoing unpleasant symptoms without proper treatment. Recurrence is possible if straining continues, so the bowel routine is often the longest-lasting part of care. Reducing risk comes down to regular bowel movements, enough fluid and fibre, and not pushing at the toilet.

See a GP if you notice blood or mucus when you open your bowels, if constipation or straining has gone on for weeks, or if you have persistent pain. The NHS advises an urgent GP appointment or NHS 111 for black or dark red stool or bloody diarrhoea, and A&E or 999 for bleeding that will not stop or a large amount of blood.

No NHS page covers this condition by name, so this guide draws on a US academic centre and a clinicians' manual as well as NHS pages on related symptoms. If you are given advice by your own team that differs, follow your team.