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Stomach or pelvic radiotherapy side effects: pain

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This page tells you about pain in the lower abdomen (pelvic area) after radiotherapy to the pelvis and what can treat the pain. There is information about


Why pain happens

After radiotherapy to the lower part of the abdomen (pelvis), you might get pain some time afterwards. Pain can occur for various reasons. It is important to see your doctor quickly if you have pain. The type of pain that happens with each cause, along with other symptoms, is described below. There is information about coping with pain in the cancer and pain control section.



Bladder infections can cause pain and are more common after pelvic radiotherapy. The pain is usually worse when the bladder is full. It may be at its worst when you are passing urine or just afterwards. Your urine may be cloudy or smelly or have small amounts of blood. You may also feel ill, have a high temperature or feel sick (nauseated). Your urine will need to be tested to find out which type of infection you have. Your doctor can then prescribe the correct antibiotic.


Bowel changes

Cramps (spasm) of the muscles lining the bowel can cause pain. This type of pain is made worse when you have your bowels open. The pain is cramp like and may come in waves. Constipation or a narrowing of the back passage (an anal stricture) can cause pain. Sometimes the pain may be due to a split in the skin of the anus known as a fissure. A fissure causes a very sharp and intense pain when you have your bowels open. You may be asked to have an examination of the bowel to find out whether there are any changes. This examination is done with a flexible sigmoidoscopy. A gastroenterologist usually does this test.


Fine cracks in the pelvic bones

Pelvic radiotherapy can sometimes cause tiny cracks in the pelvic bones some time later. It is more likely to happen in people who have general weakening of their bones as they get older (osteoporosis). It is also more likely in people who are taking hormone therapies or steroids

The tiny cracks are called pelvic insufficiency fractures. The pain in this case can be quite bad. It usually gets worse if you move around or do exercise and gets better when you sit still or rest. This type of pain normally goes away overnight. It does not stop you from sleeping well. You may be asked to have X-rays, a CT scan or an MRI scan (or a combination of these) to see if there are any fractures in the pelvic bones.


If the cancer comes back

Pain can also be caused if the cancer has come back. This is what many people who get pain after radiotherapy worry about most. You can talk to your doctor about the chance of your cancer coming back. If the pain is caused by cancer, it may be there constantly, but for some people it comes and goes. It tends not to go away when you rest. Or it may get worse when you exercise or move around. The pain may also be there at night and keep you awake. The pain may not be very bad and may go away if you take mild painkillers. However, if you have this type of pain, your doctor should examine you and should arrange for you to have X-rays, a CT scan or an MRI scan or a combination of these to find the cause.

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Updated: 4 July 2012