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Some women experience some of the following bowel problems after pelvic radiotherapy.
Bleeding from the back passage (rectum) after radiotherapy is common, but it’s usually mild and often doesn’t need treatment. Bleeding sometimes improves gradually and can stop on its own after a few years. Women who take blood-thinning medicines, such as aspirin or warfarin, may have heavier bleeding.
Bleeding may not always be a result of previous radiotherapy. It can be caused by piles (haemorrhoids) or straining on the toilet. But even if you think you know the cause, always tell your cancer doctor or specialist nurse if you have any bleeding from the back passage. It’s important to find out the cause and to rule out serious problems. Your doctor will do an examination of your back passage and may refer you to have a test to look at the inside of your rectum (an endoscopy|).
If bleeding is minor and manageable, you probably won’t need any treatment. You’ll be given advice about your bowel habits to help minimise the bleeding and avoid constipation.
If the bleeding is interfering with your day-to-day life or if you have become anaemic (when your body produces fewer red blood cells than usual), you’re likely to need treatment. If you’re taking blood-thinning drugs, your dose may be reduced and monitored. Your doctor or specialist nurse will explain more about your treatment options and give you more detailed information.
The most commonly used treatment for bleeding from the rectum is a drug called sucralfate (Antepsin Suspension®), which is given as an enema. An enema is an injection of fluid into the rectum. Sucralfate works by coating the lining of the rectum, reducing inflammation and encouraging healing. It’s important to avoid constipation| when you’re being treated with sucralfate.
A drug called formalin is also helpful for some people. It works by sealing the bleeding blood vessels. Your doctor can give it to you through a thin, flexible tube with a light on the end (endoscope), which is passed into the bowel. You can also have it done under a general anaesthetic.
If bleeding is higher up in the large bowel (colon), or isn’t reduced with enemas, other treatments may be helpful:
We have section on hyperbaric oxygen therapy|.
Tenesmus is the feeling of needing to go to the toilet often, although your bowel is empty. It can involve straining, pain and cramping. It’s probably due to cramp (spasms) in the muscles that stimulate the bowel, as radiotherapy can affect them.
The spasms can often be controlled by:
Sometimes tenesmus can be caused by constipation. It’s also sometimes caused by a non-cancerous growth (a polyp) in the bowel, or can be caused by a cancer. Your doctor will examine your back passage and may arrange for you to have a test called a flexible sigmoidoscopy, to look at the rectum and lower part of the large bowel.
After radiotherapy, some women develop a split in the skin (a fissure) where the back passage opens to the outside of the body (anus). It can cause very sharp, intense pain when you pass a stool (bowel motion). Your doctor will usually prescribe creams that you can apply to the area. It’s important to avoid constipation, as this can make the fissure worse. Your doctor may prescribe a laxative to make it easier for you to use the toilet.
If the fissure doesn’t improve, it can be treated with injections of botulinum toxin A (Botox®), which are given into the tissue lining the anus.
Feeling that you can’t wait when you get the urge to open your bowels can be stressful, particularly when you’re away from home. You may sometimes have leakage (incontinence). The degree of incontinence varies. You may just have a small amount that causes some staining on your underclothes.
Occasionally, women may have an accident and leak a larger amount of stool. Although you might find this difficult to talk about, it’s important to let your doctor know as there’s a lot that can be done to help.
If you have bowel control problems, such as urgency, leakage, diarrhoea or constipation, there are several things that can help. The best way to manage any bowel control problems depends on the symptoms you have and what’s causing them, so it’s important you’re properly assessed. If your symptoms don’t improve, ask your GP to refer you to a gastroenterologist, a specialist nurse or continence adviser for advice.
The most common methods of improving bowel control include:
Foods affect people differently so there may be some trial and error before you work out what’s best for you. Try to find out which foods cause constipation or make your bowel motions loose. You may be able to eat less of them without cutting them out altogether. Caffeine, alcohol and artificial sweeteners can also cause problems.
See our food guide| below for information about foods that can cause or improve bowel problems.
Some supplements (such as the mineral selenium, which is only needed in small amounts) can cause diarrhoea.
Fibre is important in regulating how your bowel works.
There are two types of fibre:
Your specialist nurse, continence adviser or gastroenterologist (if you’re seeing one) will advise you on the type of fibre you need and how much you should have.
If you’re adding fibre to your diet, do it gradually to give your body time to adjust. Start with small amounts and slowly increase the amount when you’re ready. Make sure you drink more water.
Adding more fibre won’t be right for everyone. After pelvic radiotherapy, you may not be able to cope with as much fibre in your diet as before. So, ‘five a day’ may not always be appropriate. Some high-fibre foods make the bowel produce a lot of gas (wind). You may need to avoid these if wind is a problem for you.
Soluble fibre supplements, such as Normacol® (an insoluble fibre), are often prescribed for people who have frequent bowel motions or incontinence. They’re also used to prevent constipation. They work by absorbing water and expand to fill the bowel, making the stools bulkier and easier to push out. Fybogel® is another fibre supplement but it makes the bowel produce a lot of gas (wind). Normacol is often a better option. You can buy some fibre supplements at the chemist, or your doctor can prescribe them. Always make sure you’re drinking plenty of fluids each day (at least two litres) when you’re taking fibre supplements.
Sometimes, radiotherapy can affect how well your bowel copes with certain food types, such as:
Symptoms of food intolerance may include tummy cramps, feeling bloated and increased wind after eating a particular food. If you think you may have a food intolerance, ask your GP to refer you to a gastroenterologist.
If changes to your diet aren’t enough to control bowel problems, anti-diarrhoea drugs may help. It’s important to speak to your doctor or specialist nurse before taking any medicines.
The most commonly used treatment is loperamide (also called Imodium® or Diareze®). It slows down your bowel, making the stools more solid and less frequent. Taking loperamide regularly, half an hour before meals, works very well for some people. It’s safe to take it for as long as you need it, but discuss this with your doctor. The dose you take may need to be adjusted until you find what works best for you. Your doctor may recommend starting with a low dose and increasing this until it’s right for you. Loperamide is also available as a syrup, so you can take less and adjust the dose as needed.
Other anti-diarrhoea tablets, such as codeine phosphate or diphenoxylate (Lomotil®), can also be prescribed. Your doctor or a continence adviser can advise you about the medicines that may be best for you.
Sometimes, low doses of anti-depressant drugs are prescribed to help slow down the bowel.
If you have diarrhoea and changes to your diet and anti-diarrhoea drugs don’t help, ask your doctor to refer you to a bowel specialist (gastroenterologist). A number of things can cause diarrhoea and a gastroenterologist will be able to assess the exact cause.
Radiotherapy can cause other conditions that can lead to ongoing diarrhoea, such as bile acid malabsorption and small bowel bacterial overgrowth.
Normally, bile acids are made in the liver and transported to the small bowel to help us digest fats. They are then absorbed back into our system. Sometimes radiotherapy damages the small bowel so it can’t re-absorb the bile acids (malabsorption). This leads to diarrhoea.
Bile acid malabsorption can be diagnosed using a scan called a SeHCAT scan. Your doctor can tell you more about this. It’s helpful to have the scan before treatment to confirm the diagnosis and the extent of its effect on you. If you have bile acid malabsorption, you’ll need to take a drug for the rest of your life to treat it, and/or stick to a low fat diet. So it’s important to get the diagnosis right.
Bile acid malabsorption can be treated with a drug called colestyramine (Questran®). It comes as a powder that you mix with water or fruit juice. Most specialists advise taking it at meal times, rather than on an empty stomach (as the instructions say), because they think it works better and is easier to take this way.
If your stool is sometimes pale, smelly and difficult to flush away, Questran may not work or may make things worse. If this happens, your specialist may prescribe a newer medicine called colesevelam (Cholestagel®). You may also be referred to a dietitian for advice on managing a lower fat diet.
A healthy small bowel contains almost no bacteria, although the large bowel contains lots of healthy or good bacteria, which help us digest food. After pelvic radiotherapy, bacteria sometimes grow in places in the small bowel where there shouldn’t be any bacteria. These can cause a number of symptoms, but the most common is diarrhoea. Other symptoms include fatty stools, wind, bloating, constipation, feeling sick, vomiting or bad breath.
Small bowel bacterial overgrowth is usually treated with antibiotics.
Some women notice that, when their bowel motions are loose, they are also paler than usual and much more smelly. The stool may float and be more difficult to flush away, and there may be a film of oil on the toilet water. This is called steatorrhoea.
It can be caused by:
If you have symptoms of steatorrhoea, you should ask to be referred to a gastroenterologist, who will be able to help you. Steatorrhoea can usually be treated effectively.
Exercises to strengthen the muscles used in bowel control can help you manage urgency, leakage and incontinence. Some women find they also help with wind|, bowel cramps and tenesmus|. The exercises work the muscles around the back passage and a deeper layer called the anterior pelvic floor muscles. These muscles also help with bladder control and are used during sex.
Ask your doctor to refer you to a continence adviser, who will teach you how to do the exercises correctly. You can read more about pelvic floor exercises in our section on bladder changes|.
The Bladder and Bowel Foundation| also produces a fact sheet with instructions on how to do these exercises. You can order the fact sheet or download the information from their website.
It’s important to:
You need to do your exercises for at least three months to properly strengthen these muscles.
Normally our pelvic floor muscles work without us consciously controlling them. As a result, you may find it difficult to know if you’re doing the exercises correctly.
Biofeedback training| can help you with your pelvic floor exercises and bowel control. Your continence adviser can tell you where you can get this training.
In addition to making changes to your diet, taking medicines to slow your bowel and doing bowel control exercises, there are other things you can do to improve bowel control. Your doctor, specialist nurse or continence adviser can advise you about these.
Some of the following may also help:
Read our section on coping with bladder or bowel changes| for advice on skin care, going out and lifestyle changes that may help you cope.
After radiotherapy, some women have more wind because their pelvic floor muscles are weaker. Although it can be an embarrassing problem, you may be more aware of it than the people around you.
The amount of wind we produce is the result of how healthy bacteria and digestive enzymes in our bowel combine with the foods we eat. Some foods, particularly high-fibre foods, such as vegetables and pulses, cause more wind than others.
This guide will help you choose foods that may help with some bowel problems. It can also help you identify foods that may make some bowel problems worse. This is only a guide, as foods can affect people differently.
These foods should be limited if you have problems with diarrhoea, loose stools or frequent bowel movements. These foods may be helpful if you have constipation.
Very occasionally, women may experience other bowel problems as a result of pelvic radiotherapy:
Radiotherapy may cause a tight band of scar tissue to develop at the opening of the back passage. This causes it to narrow (anal stricture). This can cause difficulty and pain when you try to open your bowels. If it’s mild, your doctor will advise you to use a stool-softener laxative or fibre supplement to make it easier to go to the toilet, which will help stretch the stricture. If the narrowing is more severe, you may be referred to a bowel specialist to have the opening stretched (dilatation) or to have an operation under general anaesthetic to cut through the scar tissue.
An area of bowel tissue may break down (ulcerate) and not heal. This can cause watery diarrhoea with blood or mucus in it, and pain and cramping when you go to the toilet. It’s often treated with hyperbaric oxygen therapy|.
A blockage (obstruction) in the bowel can cause sickness (vomiting), pain in the tummy and constipation. You may be given fluids through a drip to rest the bowel and treatment for constipation. Sometimes an operation to remove the blockage is necessary.
This is an opening that forms between two parts of the body. Rarely, an opening can develop between the back passage and vagina after pelvic radiotherapy.
We have a section on fistulas|, which has more information.
Very rarely, a hole may develop in the bowel wall. This is called a perforated bowel. This can make you suddenly unwell and is usually treated straight away with an operation to remove the affected part of the bowel.
Read our section on coping with bowel changes| for more information.
Content last reviewed: 1 July 2012
Next planned review: 2014
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