You might have pain in your pelvis (the area between the hip bones) after radiotherapy. This can happen sometime after your radiotherapy has finished.

Let your health care team know if you have any pain during or after your treatment. 

Possible reasons for pain can include: 


Bladder infections can cause pain and can be common after pelvic radiotherapy. The pain is usually worse when the bladder is full. Or when you are passing urine.

If you have a bladder infection your urine might be cloudy or smelly or have small amounts of blood. You might also feel ill, have a high temperature or feel sick. 

Your doctor might arrange a test to check your urine. This is called a midstream urine (MSU) test. Your doctor can then prescribe the correct antibiotic if you do have an infection.

Bowel changes

Radiotherapy can cause bowel changes, such as cramps and constipation.

Cramps (spasm) of the muscles lining the bowel can cause pain. This type of pain is made worse when you open your bowels. The pain might come in waves. 

Constipation or a narrowing of the back passage (an anal stricture) can cause pain. Sometimes the pain can 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 open your bowels. 

Your doctor might ask you to have an examination of the bowel after radiotherapy to find out whether there are any changes. This is done by putting a flexible tube into the bowel (a flexible sigmoidoscopy). A specialist in bowel problems (gastroenterologist) usually does this test.

Pelvic bone changes 

Radiotherapy for cancer in the pelvic area can sometimes lead to hip and pelvic bone problems later in life. Radiotherapy can damage bones in different ways.

Problems after pelvic radiotherapy may include weaker bones and tiny cracks in the bones.

Weaker pelvic bones 

Radiotherapy can damage the bone cells in the pelvic area, and also lower the blood supply to the bones. The bones become weaker. This is called avascular necrosis. Damage to the bones can cause pain and sometimes makes it hard to walk or climb stairs.

Let your doctor know if you're having problems and they will monitor you carefully, including checking your bone strength with a DEXA scan. They might suggest treatment with painkillers and walking aids to help you get around, such as a stick. You might also need to take medicines to strengthen the bones called bisphosphonates. These drugs can help to control pain and reduce the risk of fractures.

Tiny cracks in the bones 

Sometimes, tiny cracks can appear in the pelvic bones some years after treatment. They are called pelvic insufficiency fractures. This is more likely to happen in people who have a 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 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 doesn't stop you from sleeping well. Your doctor might ask you 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 bones.

Cancer coming back

You might experience pain if the cancer has come back. This is something that people often worry about, but there are many other reasons why you might have pain. You should go and see your doctor so that they can find the cause.

Pain from cancer coming back can vary from person to person. For example, you might feel pain all the time or it might come and go.

For some people, they are still in pain when resting or it's worse when they move around or exercise. It can make sleeping difficult. Mild painkillers might help. 

If you have pain that doesn't go away, your doctor should examine you. They can arrange for you to have X-rays, a CT scan or an MRI scan or a combination of these to find the cause.

  • Devita, Hellman and Rosenberg's Cancer Principles and Practice of Oncology (11th edition)
    VT Devita, TS Lawrence and SA Rosenberg
    Wolters Kluwer Health, 2019

  • Insuffiency fracture after radiation therapy
    D Oh and S Huh
    Radiation Oncol Journal, 2014. Vol 32, Issue 4, Pages 213-22

Last reviewed: 
12 Nov 2020
Next review due: 
12 Nov 2023

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