Long term side effects of anal cancer radiotherapy
Side effects of radiotherapy to the anus tend to gradually go away in the weeks or months after treatment. But some side effects can continue. Or you might notice some begin months or years later. These are called long term side effects.
Most of these side effects are rare. If you do get any of them, there are things you or your healthcare team can do to help manage them.
Smoking and long term side effects
If you smoke, stopping before you start radiotherapy treatment is a good idea. It can help reduce the side effects caused by treatment and improve your general health.
Stopping smoking can be difficult, particularly when going through a stressful time. There are a range of support services and different products to help you. Talk to your doctor or nurse about support for stopping smoking.
If you get any long term side effects
Talk to your doctor if you have developed any of these effects. It may be that your symptoms are due to something else, such as a bowel or bladder infection. If it is due to your treatment, your doctor or nurse can help manage your symptoms.
Bowel and bladder changes
Frequent or loose poo
Your bowel movements might be looser or more frequent than before your treatment. And sometimes you might pass some blood from your back passage (rectum).
You might need to take anti diarrhoea medicines, such as loperamide (Imodium). Bulking agents, such as Fybogel, might also help. Your doctor or nurse can prescribe these for you. Talk to your doctor before taking these.
It’s usually best to try to have a healthy balanced diet if you can. Try to eat small meals and snacks regularly. Ask with your healthcare team if you need to make any changes to your diet. Some people find it best to avoid high fibre foods such as beans, nuts, seeds, dried fruit, bran and raw vegetables.
Drink plenty to try and replace the fluid lost. Aim for 8 to 10 glasses per day.
Let your doctor know if you have ongoing problems with frequent bowel movements or bleeding. They can refer you to a specialist team. The team includes:
- cancer doctors
- digestive system specialists
- bowel surgeons
- dietitians
- specialist nurses
Difficulty controlling your bowels and bladder
Radiotherapy to your 
may weaken the muscles in your anus and bladder or damage the nerves. This can make them difficult to control and you may find you poo or pee without realising it.
Not being able to control your bowels is called faecal incontinence. And not being able to control your bladder is called urinary incontinence.
Talk to your doctors or nurse if you have problems controlling your bowels or bladder. They can refer you to a physiotherapist or community continence advisor for advice and information.
Your nurse, physiotherapist or continence advisor might give you information about pelvic floor exercises which can help. And a continence adviser can give you pads if you need them.
Incontinence can make the skin around the area sore. Ask about any creams you can use to protect the skin.
You can get details of your nearest continence service or advisor from Bladder and Bowel UK. And you may be able to refer yourself to your local service.
Other bladder changes
Some people can have other changes to their bladder after radiotherapy. It can lead to:
- the bladder wall being less stretchy - so you have to pass urine more often
- fragile blood vessels forming in the bladder wall – this can cause blood in the urine
- the tube through which urine passes out of the body (urethra) becoming narrower – this can make it difficult to pee
Tell your doctor if you get any of these changes. It is important they check that these aren’t caused by any other health problems.
'Just can’t wait' card
You can get a card if you need to go to the toilet more often. Or feel that you can’t wait when you do need to go. You can show the card to staff in places such as shops or pubs. It allows you to use their toilets, without them asking awkward questions.
You can get the cards from Disability Rights UK or Bladder and Bowel UK.
RADAR key
Disability Rights UK can also give you a key for disabled access toilets so that you don't have to ask for a key when you are out. This is also called a RADAR key.
Pain in your back passage (rectum)
Some people have long term discomfort or pain in their rectum after treatment. Tell your doctor if you are struggling with these symptoms. They can suggest treatments to help.
Changes to your sex life
Changes to the sex organs may appear sometime after treatment. This can cause side effects that may affect your sex life such as a low sex drive.
Men may also find it difficult to get an erection after treatment. And women may have dryness and shrinkage of the vagina. This can make sex painful. Using vaginal dilators after treatment can minimise this. Some women can also have early .
Talk to your doctor if you think you have developed any of these side effects. There are ways of reducing and managing them.
Loss of fertility
Unfortunately, both men and women might be unable to have children after radiotherapy for anal cancer. Your doctor will talk to you about this before you start treatment. Tell them if you are thinking about having children in the future.
Damage to your hip and pelvic bones
Radiotherapy to the pelvis can damage the bones in the pelvic area. The bones can become weaker. This can cause pain and also increases the risk of breaking your pelvic or hip bones.
Your doctor will monitor you carefully. This may include checking your bone strength with a bone density scan. They might suggest treatment with painkillers and walking aids to help you get around, such as a stick.
Bisphosphonates
Sometimes your doctor might suggest you take a type of medicine called a bisphosphonate. They help prevent or slow down bone weakening. And they also help control pain and reduce the risk of fractures.
Low levels of vitamin B12
You might have low after radiotherapy to the pelvis (the area between your hip bones). This is called a vitamin B12 deficiency.
Radiotherapy can stop your from taking in (absorbing) vitamin B12 from the food you eat. This is called malabsorption. This means you can have a B12 deficiency even if you eat a balanced diet.
A B12 deficiency can be a cause of . This can lead to weakness, diarrhoea, numbness and tingling.
It’s important that you go to your doctor if you’re experiencing these symptoms so that they can help you.
Lymphoedema
Radiotherapy to the pelvis and to such as those in the groin (inguinal lymph nodes) can cause scar tissue. This can affect the flow of and cause it to build up causing swelling called lymphoedema. After pelvic radiotherapy you can get lymphoedema in the tummy area, genitals or legs.
Lymphoedema is a chronic condition that can be managed by a lymphoedema specialist. If you notice any swelling, speak to your doctor or specialist nurse. They can refer you to a lymphoedema service.
