Radiation enteritis: bowel effects of radiotherapy

Enteritis means inflammation of the bowel, and radiation enteritis is the name used when the cause is radiotherapy. It can follow radiotherapy to the abdomen or pelvis, because the bowel sits within or next to the treated area. This page uses Macmillan, Cancer Research UK and PRDA information, which describe the effects under bowel side effects and pelvic radiation disease.

Macmillan says most people have side effects during pelvic radiotherapy, which usually improve over a few weeks or months after treatment ends. Sometimes they do not go away or start later.

Cancer Research UK says the main side effects of abdominal or pelvic radiotherapy include diarrhoea, sickness, weight loss, bladder problems and pain. Bowel habit may change during radiotherapy and afterwards. You might need to open your bowels urgently, go several times before the bowel feels empty, feel the need to go when the bowel is empty (tenesmus), pass more wind or pass mucus from the back passage.

Radiotherapy can also cause bowel cramps and constipation, and the charity notes that the pain can be worse when you open your bowels. Diarrhoea can make you weak and tired, so rest, and drink plenty of fluid because dehydration is easy. Your radiotherapy team can offer anti-diarrhoea drugs, anti-spasm medicines and diet advice.

Macmillan describes four types of change. Radiotherapy can damage the bowel lining and small blood vessels, which may cause bleeding. It can cause scarring (fibrosis) in the large bowel, making it narrower, thicker and less flexible, so waste passes faster and stool may be softer or liquid. It can affect the muscles that keep stool in the rectum, causing leakage. And it can alter the small bowel, causing food intolerance, bile acid malabsorption or small bowel bacterial overgrowth.

Symptoms may include rectal bleeding, mucus, painful cramps, difficulty emptying, tenesmus, diarrhoea, constipation, urgency, incontinence and a lot of wind. Some people have mild changes, such as going to the toilet twice a day instead of once. For others the impact is large and affects appetite, weight and daily life.

Macmillan says there are 4 symptoms you must always talk to your doctor about: passing blood from your back passage, waking up from sleep to open your bowels, needing to rush to open your bowels and bowel incontinence. It adds that ongoing bowel symptoms might not be caused by radiotherapy and can signal something more serious, including a return of the cancer, so they need to be checked.

Contact your cancer team promptly, or seek urgent care, if you have heavy rectal bleeding, severe or worsening abdominal pain with vomiting, a swollen tummy, signs of dehydration such as dizziness or very little urine, or a high temperature. Use NHS 111 out of hours, and call 999 for severe pain, collapse or heavy bleeding.

Macmillan says your doctor or nurse checks your symptoms and you may need tests to learn more and check for other causes. Cancer Research UK mentions an examination of the bowel with a flexible tube, such as a flexible sigmoidoscopy, which a bowel specialist usually does.

At hospital follow-up, the specialist assesses late effects and how they are being managed, and checks for signs of the cancer coming back. Telling your team about every bowel symptom, however embarrassing, gives them the information they need. Macmillan notes that doctors and nurses are used to speaking about these problems.

The right treatment depends on which symptoms you have and how much of a problem they are. Cancer Research UK lists anti-diarrhoea medicines, anti-spasm medicines, drinking plenty and changing your diet, and suggests speaking to the radiotherapy team or a dietitian. If bile acid malabsorption or bacterial overgrowth is the cause, specific treatments exist, so say if simple measures fail.

Macmillan says you may be referred to a gastroenterologist, a colorectal surgeon, a continence advisor, a stoma care nurse, a late effects specialist or a physiotherapist, and that a few hospitals have late effects clinics. The Pelvic Radiation Disease Association offers information, a diet and nutrition guide, a best practice pathway and support for people living with late effects.

Most early effects settle. Cancer Research UK says they usually improve within a few weeks of finishing, while Macmillan says side effects usually improve over a few weeks or months, though diarrhoea can also be a long-term effect. Late effects do not affect everyone, and when they occur there are usually things that can help you cope.

The Pelvic Radiation Disease Association exists because some people find that bowel problems continue after cancer treatment has finished, and its patient stories show others in the same position. Persistent problems should be raised rather than accepted.