Bowel changes after pelvic radiotherapy
Sometimes, women who have had pelvic radiotherapy notice changes in the way their bowel works. For some women, these changes start during treatment and don’t get better. But for others, the changes may develop months or years after treatment.
The bowel is part of the digestive system. It’s made up of the small bowel and large bowel. The small bowel absorbs nutrients from the food we eat. It then passes the liquid waste into the large bowel (colon and rectum). The colon absorbs water from the waste before passing the more solid waste (faeces or stool) into the rectum. The stool is held in the rectum until it’s ready to be passed through the anus (the opening to the outside of the body).
Radiotherapy can cause scarring (fibrosis) in the large bowel lining, making it thicker and less flexible. This causes solid waste to pass through more quickly than before, so nutrients may not be as well absorbed. The bowel will also be unable to hold as much solid waste (stool). The muscles that help to hold stool in the rectum can also be affected, which may cause problems with bowel control and leakage (incontinence).
The blood supply to the bowel can also be affected by radiotherapy, making the bowel tissue and the small blood vessels in it more fragile. Radiotherapy can cause the bowel to narrow. When radiotherapy affects the small bowel, it can cause food intolerances, or conditions such as bile acid malabsorption or small bowel bacterial overgrowth.
Some women find that their symptoms don’t cause them too many problems, and that they can manage them fairly easily. Others may have more severe changes that interfere with how they live their day-to-day lives.
The symptoms of late effects to the bowel can include:
bleeding from the back passage (bottom)
passing mucus (a clear, sticky substance)
cramps or spasms in the bowel and/or feeling that you haven’t emptied your bowel completely (tenesmus)
diarrhoea or severe constipation
needing to rush to open your bowels (urgency)
leaking or soiling (incontinence)
passing a lot of wind.
The change in the way the bowel works may be slight, for example, having to go to the toilet twice a day instead of once. But sometimes bowel changes can have a much greater impact, interfering with day-to-day life.
There are lots of ways of managing or treating your symptoms. Your doctor can advise you, or they may refer you to a specialist in bowel problems (a gastroenterologist) for tests.
You may also be referred to a specialist nurse or physiotherapist for advice and treatment on incontinence (we use the term continence adviser because it’s shorter).
There are three problems 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, or having accidents.
These symptoms may not be due to anything serious, but should always be checked out. They often respond to simple treatments. Occasionally they can be a sign of a more serious problem, so it’s important to find out the cause as soon as possible.
Tests can include blood and stool tests, x-rays and scans. You may have a test to look at the inside of your bowel. This involves a doctor or nurse passing a thin tube with a light on the end (an endoscope) into the bowel to look for any abnormal areas.
Occasionally, people need to have a sample of tissue removed (a biopsy) from the bowel, but this should only be done by an experienced bowel specialist.