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During radiotherapy to the pelvic area, inflammation of the large bowel (colon and rectum) and anus occurs.
Inflammation may cause symptoms such as:
Once the radiotherapy has ended, the inflammation usually settles down over a few weeks or months and the way the bowel works goes back to normal. It may take six months or more for the bowel to settle into a regular pattern. However, the bowel is often permanently scarred by the radiotherapy and most women will have a permanent change to their bowel habit.
The change in the way that your bowel works may be very slight, for example, having to go to the toilet twice a day instead of once. However, up to half of women who have had pelvic radiotherapy find that the change in the way their bowel works affects their day-to-day life. Up to 1 in 3 women (33%) need to go to the toilet very often. They are not able to easily work, travel or carry on life as normal. Bowel problems may make you feel very tired and worn-out.
Problems that may continue for some women after radiotherapy are mentioned below with ways of dealing with them.
Up to 1 in 2 women (50%) who have had pelvic radiotherapy get a loose stool or diarrhoea from time to time afterwards. This may just happen occasionally or may be quite often. The loose stool or diarrhoea may be because the bowel is a little less flexible after radiotherapy, so food travels through more quickly.
In some people, diarrhoea may be caused by specific things in the diet, such as:
If you want to make changes to your diet it's a good idea to ask your cancer specialist or GP to refer you to a dietitian for specialist help.
If you can’t carry on a normal life because of the diarrhoea, you can ask your doctor to prescribe anti-diarrhoeal medicines such as loperamide (Imodium™, Arret®), codeine phosphate or diphenoxylate (Lomotil®). Some people may need to take them in higher doses than usually prescribed. They are safe to take for an unlimited time. Your specialist or a continence adviser can advise you about when to take the medicines as this can affect how effective they are. Most work best when they are taken half an hour to an hour before a meal.
If the anti-diarrhoea drugs do not help, let your doctors know. The radiotherapy may have caused a condition called bile salt malabsorption or another condition called small bowel bacterial overgrowth which can be treated with specific medicines. You can get factsheets with detailed information about these conditions from the Royal Marsden Hospital|. If your diarrhoea is causing you problems and your cancer specialist is not sure what to do, you can ask them to refer you to a bowel specialist (gastroenterologist).
Many people have this problem after pelvic radiotherapy. It can happen especially in the morning and some people have to go several times before they feel the bowel is empty. This may be because the radiotherapy makes the bowel less stretchy so it can’t hold as much stool. You may find that it helps to take anti-diarrhoea medicines or do regular anal sphincter exercises, and pelvic floor exercises|. You can practice holding on to the stool to build up the capacity of the bowel.
If you need to go to the toilet often (or at night) and also have some bleeding from your bottom it's important to tell your cancer specialist. It's also important to tell your doctor if you lose weight or if you sometimes get constipated and can’t go. They can refer you to a bowel specialist (gastroenterologist).
Bleeding from the back passage (rectum) after radiotherapy is very common. This is because the radiotherapy makes the blood vessels in the lining of the bowel more fragile. Bleeding can also happen:
Bleeding can also be a sign of some serious conditions (including cancer) so it's important that you tell your doctors if it happens so that they can investigate what the cause is.
Your doctors may recommend that you have tests which will probably include an examination of the bowel, using a flexible tube with a light and lens on the end (a flexible sigmoidoscope). You can ask your doctor if they think it is necessary for you to have this done.
If the bleeding is caused by damage to the small blood vessels in the lower part of the bowel, it usually improves gradually over many years. It is rare for the bleeding to be heavy or to cause any other long-term problems. However, people who take blood-thinning drugs such as warfarin or aspirin may find that the bleeding is heavy. Your doctor or specialist nurse can give you advice about this.
If the bleeding is minor or not a problem for you, you will probably not need any further treatment.
If the bleeding is heavy or is a problem for you, you may be prescribed a drug called sucralfate (Antepsin suspension®), which is given as an enema. This drug helps by coating the lining of the rectum and may reduce inflammation and bleeding. It is important to make sure that you don’t get constipated.
If the bleeding is very heavy, it may be possible to stop it with laser treatment. Using an endoscope (a thin, flexible tube with a light and lens at the end), a laser is directed at the inflamed and damaged areas.
An enema containing the drug formalin given into the rectum can be helpful for some women. High pressure oxygen treatment (hyperbaric oxygen therapy|) has also been shown to be useful.
Any treatment that you need will be explained to you by your doctor or specialist nurse.
Not being able to get to the toilet in time is one of the most embarrassing things that can happen to anyone. Up to 2 in 5 people (40%) who have had pelvic radiotherapy may find at some time or other that they can’t get to a toilet in time or that their bowels open without any warning (faecal incontinence). For a small number of women this may happen regularly.
If this happens, it can have a huge impact on your life. You may find it embarrassing to talk about, but it's important that you let your doctor or a specialist nurse know. A lot can be done to help. If you have problems controlling your bowels, you can ask your doctor or nurse to refer you to a bowel specialist (gastroenterologist) or a continence adviser.
These accidents can happen because the radiotherapy may make the lining of the bowel thicker and less flexible so it can’t hold so much stool. This can make it difficult to hold on to the stool until you get to a toilet. The radiotherapy may also have an effect on the muscles of the anus. These muscles usually prevent the stool coming out of the anus.
Understandably, many people who have had an accident feel very panicky that it may happen again when they feel a sensation in their bowel. Feeling panicky can make the bowel work faster and can make accidents more likely. Previous damage to the bowel during childbirth can make the chance of leakage higher.
Your doctor or a continence adviser can advise on all sorts of ways to improve bowel control.
Some of the following may help:
Keep a diary of how your bowel is working so your doctor or a continence adviser can work out what might help you. You can use this symptom diary [PDF, 903kb)]| to help keep a record.
If you find it difficult to control your bowels, it's very important to talk to your doctor or nurse, or a continence adviser at your hospital. Many things may help you to go back to leading a normal life, without the worry of needing to be near a toilet or that you will have an 'accident'.
If you are too embarrassed to talk to people you know, you can contact The Bladder & Bowel Foundation. They can tell you about your nearest continence clinic or continence adviser. There are over 400 continence advisers and many continence clinics in the UK. The website www.bowelcontrol.org.uk| also gives information and practical advice on dealing with bowel problems.
If you need to go to the toilet more often and feel you can’t wait, you can get a public toilet key that gives you access to around 7,000 locked public toilets around the country. This can help you to get into toilets quickly and feel less worried when you go out. You can also get a Just Can’t Wait card to show to staff in shops and pubs etc. The card explains that you have a medical condition that requires urgent need of a toilet.
You can get a toilet key or a Just Can’t Wait card from The Bladder & Bowel Foundation| or RADAR|.
Pads are available from your district nurse or GP. They may be available on the NHS or you may need to pay for them. Continence advisers, specialist nurses and our cancer support specialists can advise you on caring for your skin if it gets sore.
This is common after radiotherapy. It is probably due to cramp (spasms) in the muscles which stimulate the bowel. The bowel is a muscular tube and the bowel muscles squeeze the stool down and out of the bowel. Radiotherapy may sometimes change the way the bowel muscles work. So after you have tried to open your bowels, your muscles may carry on contracting. This makes it feel like something is left behind. This feeling is called tenesmus.
Tenesmus can occasionally be due to a polyp (a benign growth) in the bowel or a bowel cancer. So, if you have tenesmus, your doctor will need to examine your back passage with their finger. They may recommend that you have a test called a flexible sigmoidoscopy. A doctor or specialist nurse uses a flexible tube with a light and lens on the end to examine the lower part of the bowel.
In most people with tenesmus, the sigmoidoscopy will find it isn't due to a cancer. Often the spasms can be controlled using pelvic floor exercises, taking some extra fibre to bulk up the stool or using very low doses of antidepressants.
Some people find that they don't have very good control of wind. Pelvic floor exercises| should help. There can be many reasons for wind, but the most common is eating too many vegetables that create gas in the bowel. Any food that contains starch (complex carbohydrates) and dietary fibre will go through a process in the bowel that produces gas. Foods most likely to cause gas include:
Many people diagnosed with cancer start to eat more 'healthily' which often includes more vegetables and this can lead to more wind. Another cause of wind is constipation, as the bacteria living in the bowel have more time to produce gas. Some common bowel conditions such as diverticular disease, may also make people feel they have wind. Some medicines can also produce gas, such as lactulose and fybogel.
Iif wind is a problem, it is important to think about your diet |. You may be having too much fibre. If you usually have slow or normal bowels or have had diverticular disease in the past, it can help to regularly take a medicine to bulk up the stool, such as normacol granules. The bulking-up medicines make the stool travel through the bowel a bit quicker.
Rarely, wind may be caused by too many bacteria growing in the small bowel – this is called small bowel bacterial overgrowth and can be helped by antibiotics.
After pelvic radiotherapy, up to 1 in 10 people (10%) may get pain| from time to time. The pain is often due to some of the problems mentioned above. Some painkillers can cause constipation and may make bowel problems worse, so it's important to ask your doctor, nurse or continence adviser which painkillers could help you.
Some people may have difficulty opening the bowels properly or feel pain when they try to open their bowels. The anal opening may feel too tight or narrow. This can be caused by a tight band of scar tissue that narrows the opening of the anus (known as an anal stricture). If this is mild, your doctor may recommend that you use a stool softener or fibre supplement to help ease your bowel movements past the narrow anal opening. If the narrowing is more severe, you can be referred to a bowel specialist who will either carefully stretch (dilate) the anal opening or surgically cut through the scar tissue. These procedures are usually done under a general anaesthetic.
Some people notice that when their bowel motions (stools) become loose that they also become pale and much more smelly. The stool may float and be more difficult to flush away. There may also be a film of oil floating in the water of the lavatory pan. This is a called steatorrhoea.
Steatorrhoea can be caused by:
Steatorrhoea can usually be easily treated. You need to ask to be referred to a specialist in treating bowel conditions (gastroenterologist) who should be able to help you.
For a lot of women, the way their bowel works will go back to almost normal after their radiotherapy. However, some women will then develop some of the above side effects many years later (up to 15–20 years). Other bowel problems that can happen to anyone and are not due to the radiotherapy may also occur in the years after treatment.
If you develop any new bowel problems after your treatment, or if any immediate side effects get worse, it’s important to tell your doctor or specialist nurse quickly. Tests can then be done to find out what is causing the problem so that ways can be found to control it. It can be difficult to talk about bowel problems but doctors and nurses are used to discussing these issues so you don’t need to feel embarrassed.
In a small number of women – up to 3 in 20 (15%) – very serious side effects can occur at some stage, often years after treatment. These include the following:
These symptoms aren’t always caused by radiotherapy and could be caused by other, less serious conditions. However, if you develop any of them you should contact your doctor as soon as possible, as you may need urgent treatment.
Radiotherapy can slightly increase the risk of developing cancer of the bowel within the treated areas. However, the risk of developing a new cancer is usually far outweighed by the benefits of having the radiotherapy. A colonoscopy, 5-10 years after the end of the radiotherapy, can sometimes be helpful to look for pre-cancerous changes (polyps) in the bowel. Your doctor or specialist nurse can discuss this with you.
Tests to find out what is causing the problem may include blood and stool tests, x-rays and scans. Your doctors may want to look into your bowel using a colonoscope|, a thin, flexible tube with a light on the end. This is passed into the bowel and any abnormal areas can be seen.
You may be referred to a bowel specialist (gastroenterologist) for tests. Some continence clinics can also carry out tests.
For answers, support or just a chat, call the Macmillan Support Line free (Monday to Friday, 9am-8pm)
If you have any questions about cancer, need support or just want someone to talk to, ask Macmillan.