What is a normal bowel habit?
People vary a lot in how often they open their bowels – usually between three times a day and three times a week in the UK. Interestingly, people living in different parts of the country and people from different ethnic backgrounds may have different bowel habits, possibly because of variations in their diets. A stool should be solid, but moist and easy to pass.
How the bowel works
Contraction and relaxation of the colon and rectum are regulated by three separate parts of the nervous system (sympathetic, parasympathetic and enteric nervous systems). Physical disorders affecting these pathways will influence how often you need to open your bowels. The activity of muscles in the colon is also stimulated by factors such as food and emotion. When there are sufficient faeces in the rectum to distend it, this causes its smooth muscle to contract in
a reflex action and also makes the internal sphincter muscles (which keep the anus closed) relax. The stool is then expelled when we contract the diaphragm and abdominal muscles, and relax the pelvic floor muscles and external sphincter muscles.
What is constipation?
Constipation is largely a subjective sensation and has no universally accepted definition. A person can be considered to be constipated when fewer than three bowel actions happen in a week, or if there is often a need to strain to pass a stool. Constipation is hardly ever harmful in that you won’t become ‘poisoned’ or ‘dirty’ if your bowels don’t open. Although constipation is not a disease, it is occasionally a symptom of an underlying disease.
What causes the usual types of constipation?
There are several simple explanations for most constipation. It is often caused by an unsuitable diet, bad bowel habits or not using the muscles effectively:
Diet: usually a lack of fibre (roughage) in the diet.
Bad bowel habits: most people have an urge to go to the toilet once or twice a day. This often happens after a meal. If this urge is ignored, the stool dries out and becomes hard. The next bowel movement may then be difficult or painful.
Uncoordinated straining: some people do not strain effectively and/or fail to relax the muscles around the back passage when they strain.
Your abdomen may feel uncomfortable or bloated and you may have a sense of fullness above your back passage (rectum and anus). Straining can lead to piles (see page 57), which may bulge at the anus or bleed. Women may also find intercourse uncomfortable if the bowel is very full.
What causes constipation?
The most common causes of constipation are simple and easily put right. If your diet does not contain enough fibre, it is more difficult for your bowel to pass food along and keep the faeces soft enough to pass easily. Modern lifestyles make it difficult to respond immediately to the urge to empty your bowels.
Ignoring this urge means that the faeces are stored longer and they can become hard and dry.
Some people do not strain effectively or fail to relax the anal muscle to allow the rectum to empty. Retraining the use of the muscles will help this problem.
What makes constipation worse?
Your bowel function is affected by many factors. These can make any tendency to constipation worse.
You must drink enough fluid each day – about two litres. If you become dehydrated, your faeces will become harder.
Physical exercise massages the bowels and helps the passage along the gut, so inactivity will make any constipation worse.
Your emotions have a strong effect on your bowels. Anxiety can speed the passage along your bowels, but other emotions can slow it down and lead to constipation.
Painful conditions that affect the anus will aggravate any constipation. Piles are the result of straining, which you are more likely to do if you are constipated. As they are painful it makes it harder to respond to a need to empty the bowels. Working hours can interfere with a regular bowel habit. You may have to be at work early in the morning and leave home before you have emptied your bowels. Or you may work shifts that interfere with your normal body rhythm. A lack of suitable toilet facilities can aggravate constipation. Many people need to feel comfortable before they can empty their bowels.
What disorders cause constipation?
A number of organic and functional disorders can affect bowel movement. Any obstruction of the bowel as a result of scarring or inflammation or the growth of a tumour can lead to constipation. The pressure of an enlarged uterus and other changes in pregnancy can affect bowel movement. An underactive thyroid gland often results in constipation. Any alteration in the nerves or muscles that control bowel movement, as happens in IBS, can lead to constipation.
What medicines cause constipation?
Medications all have some effects other than those for which we take them. One of the side effects is constipation. All side effects from medication should be explained on the patient information leaflet that comes with the medication. Those medications that are known to be likely to cause constipation are listed in the box on page 56.
What is fibre and how does it help?
Fibre is found in the tough fibrous part of fruit and vegetables. In particular it is found in the stalk and on the outside of fruits, seeds or grains (bran is the outer covering of wheat grains). It is also in the soft parts of fruit and vegetables that are not digested by the small intestine.
Much of the food that we eat is digested in the stomach and small intestine and is absorbed as nutrients. Fibre is not broken down in this way but passes to the large intestine (colon).
Here it:
acts like blotting paper, keeping water in the stool
provides material that encourages the multiplication of useful bacteria in the colon.
Both these effects make the stool larger, softer and easier to pass. Bulky stools stimulate your gut wall, increasing the propulsive waves of contraction (peristalsis) so that they pass through more easily. Dietary fibre is found only in foods that come from plants – for example, cereals, fruit and vegetables. It is not found in animal foods. So, if you need to increase your fibre intake, gradually start to use the foods listed on pages 58–61. If you already eat some of them, try to do so more often. You may experience some increase in the amount of gas in the intestines (flatulence) and this may lead to abdominal discomfort at first. This should lessen as your body becomes used to the change in your diet. Drink plenty of fluids (at least four pints a day) because the fibre will absorb water. It may be helpful to discuss what you eat with a dietitian.
Foods containing a good source of fibre
There is a wide variety of appetising foods that contain fibre. They are all foods that come from plants: Wholemeal bread: eat this regularly in preference to white, brown or wheatmeal bread or try other varieties such as granary, Hibran, highfibre white and oatbread. You could also try wholemeal muffins, scones, crumpets, pitta bread and chapatis. Bread is good for you, so eat plenty.
Wholegrain and highfibre breakfastcereals: for example porridge muesli Weetabix Shredded Wheat, BranFlakes, AllBran. Have some everyday.
Wholemeal flour: try using equal quantities of wholemeal flour and white flour in cooking (don’t sieve the flour). You will need to add more fluid for pastry and chapatis.
Biscuits and crackers: instead of biscuits and cream crackers made with white flour, have digestive bran biscuits, flapjacks, oatcakes/oat biscuits, cereal bars, wholewheat crackers and wholegrain crispbreads.
Brown rice: this takes longer to cook than white rice, but it is more nutritious.
Wholemeal pasta: for example, spaghetti, macaroni, lasagne.
Pulses: these include dried peas, beans, lentils, dhals and tinned beans. The dried ones need to be soaked and boiled vigorously for at least 10 minutes. They can then be cooked for the remainder of the recommended time. Try using them in soups and to replace some of the meat in stews and casseroles. They can be cooled and used in salads.
Vegetables: eat some every day. Wash them well and eat lightly cooked or raw and try crunchy side salads with your main meal and lunchtime snack. Eat plenty of potatoes as they are good for you (especially in their jackets).
Fruit: eat fresh (wash well), dried or tinned in natural juices. Eat some every day. Prunes and prune juice are particularly good at relieving constipation. Add dried fruit to cereals and milk puddings, and use in baking.
Nuts and seeds: for example, sunflower seeds. Eat as a snack or use in salads or cooking. Do not give whole nuts to children under five as there is a risk of the child choking or going on to develop a nut allergy.
Should I use natural bran?
Natural bran is the outer layer of the wheat grain, not a breakfast cereal. It adds fibre to the diet, but you should use it only if your doctor or a dietitian advises you to do so. It may be useful if your bowels are not regular, even though you eat plenty of the highfibre foods listed, but should be used only in small amounts. Start by adding one teaspoon to food or drink at three meals each day. Gradually increase the amount over the next few days if needed. One tablespoon of bran three times daily is usually enough to treat constipation.
Bran can be added to: breakfast cereals soups, stews, casseroles meat and potato pies stewed fruit puddings drinks (milk or fruit juices). It may cause some flatulence when you first start to use it.
Dietary fibre, bran and bulkforming laxatives
Some people with IBS or functional abdominal pain benefit when their doctors prescribe a highfibre diet, bran or laxatives that add bulk to the stools (bulkforming laxatives). Others, however, notice no change or even deterioration in their symptoms.
Bran
There are few studies in which the effect of bran on the symptoms of IBS have been carefully evaluated over long periods. In one such study, bran was found to improve constipation significantly, but it exacerbated diarrhoea, pain and urgency.
Bulkforming laxatives
Treatment intended to add bulk to the stools is likely to be effective for people who frequently pass small, hard stools or who pass only a painful, irregular stool every few days. A highfibre diet alone is often ineffective and a bulking agent (a fibre source that swells in the bowels to provide bulk, such as ispaghula husk) is usually required. Symptoms of gas and pain are sometimes aggravated by an increase in dietary fibre, and therefore it isn’t advisable for everyone. If your normal diet is low in fibre, try increasing your intake and adjust the amount according to the way your system responds. On the other hand, especially if your intake is very high and you are experiencing pain and distension, you may need to reduce your intake of fibre.
Combination laxatives
The bulking agent, ispaghula husk, has been shown to be particularly effective in combination with musclerelaxing (antispasmodic) drugs such as hyoscine butylbromide (Buscopan) and mebeverine hydrochloride (Colofac) (see page 99).
What if some foods don’t suit me?
Some people with IBS find that pulses, nuts, dried fruits and some vegetables cause a lot of wind or discomfort. If you find that these foods upset you, it may be better to avoid them.
Is it important to eat a breakfast?
Yes. Eating breakfast helps your bowels to start working during the morning.
The best type of breakfast is a wholegrain or highfibre cereal with some wholemeal toast. If you prefer a cooked breakfast, then perhaps include plenty of wholemeal bread and some baked beans.
Healthy eating can prevent weight increase
If you have to change what you eat to avoid constipation you may be worried about putting on weight. The foods that you will be recommended are not fattening in themselves. You just have to combine them in a healthy and balanced way.
General Use a lowfat spread Use a lowfat milk Take more exercise
Some meal ideas
Breakfast
Grapefruit or prunes
Porridge
Unsweetened muesli
Weetabix with sliced banana
Bran flakes
Wholemeal or granary toast
Snack meals
Lentil soup and wholemeal roll
Baked beans on toast or muffin
Sandwiches made with wholemeal or highfibre bread
Jacket potato with baked beans or sweetcorn filling and a side salad
Wholemeal pitta bread and humous with salad
Vegetable and bean soup with a granary roll
Fresh fruit
Bran crispbreads, cheese and tomato
Main meals
Chicken, jacket potato and sweetcorn
Wholemeal spaghetti bolognese and side salad
Vegetable curry and brown rice
Chilli con carne (with red kidney beans) with brown rice and side salad
Tuna and chick pea salad with granary bread
Lentil and vegetable casserole with jacket potato
Grilled fish, jacket potato and peas and sweetcorn
Vegetables and beans in tomato sauce with wholemeal pasta shapes
Wholemeal pizza (try adding more vegetables or beans to the topping).
Will I put weight on if I eat more bread, potatoes and cereals?
Not if you cut down your intake of fat, fatty foods, sugar and sweet foods. Bread, potatoes, rice, pasta and cereals are not fattening in themselves, but they are if you serve them with fatty sauces
If you are worried about your weight, try the suggestions in the box on pages 64–5. For more suggestions, look in your local library or bookshop for books on highfibre, vegetarian and wholefood cookery.
What if my bowels are not regular?
Always try to go to the toilet as soon as you feel the urge
Try to do this as a routine, for example, as soon as you get up, or after breakfast
Drink at least four pints of fluid daily
Eat more natural fibre
Be as active as possible, even if you have a disability
Avoid laxatives
Have your meals at the same time every day
Ensure that you have access to good toilet facilities at home and work
Take regular exercise.
When should you see your doctor?
If constipation is not responding to these simple selfhelp measures and is causing you trouble, you should make an appointment to see your doctor. Any changes in bowel habit, either sudden or gradual, should also be reported to the doctor.
You should consult him or her urgently if there is rectal bleeding or new symptoms such as abdominal pain or distension. You should also see your doctor
urgently if you suddenly become constipated for no apparent reason. You will probably not need any tests, although your doctor may want to take a blood sample. This is to make sure that you are not anaemic and that your thyroid gland is working properly. If the constipation is very bad, your doctor may wish to check whether your colon is normal by arranging one of the following at your local hospital:
A barium enema Xray: this involves the insertion into the rectum of a harmless material which shows up on an Xray, allowing the doctor to see any abnormalities.
A sigmoidoscopy or colonoscopy (inserting a flexible viewing instrument so the doctor can see the interior of the colon) – see pages 44–7.
Tests to check the function of the muscles around the back passage.
Are laxatives useful?
Constipation is usually improved by a change in your diet, and drugs are therefore not needed. Occasional use of a suitable laxative is harmless, but regular use may make you dependent on it. Stimulant laxatives, such as senna and cascara, cause changes in the colon if used regularly for many years, but can be useful occasionally for a short time. Laxatives cause gripelike abdominal pains if used in large doses. A few people will need to take laxatives regularly, but this should be done only on a doctor’s advice.
The most natural and effective types are bulk laxatives. Concentrated fibre preparations are helpful for those who find it hard to change their diet.
The choice of laxatives includes the following:
Bulk laxatives: bran, ispaghula husk, methylcellulose, sterculia. Always take them with plenty of water. They make stools larger, softer and easier to pass.
Stimulant laxatives: bisacodyl or senna which stimulates contraction of the bowel.
Osmotic laxatives: mineral salts (magnesium sulphate/Epsom salts, magnesium citrate, magnesium hydroxide, Movicol, Picolax). These retain water in the bowel, softening the stools and making them easier to pass.
Lactulose, lactitol or sorbitol sugars which humans cannot digest. They stay in the bowel and combine the properties of bulk and osmotic laxatives.
Suppositories inserted into the rectum which soften the stool and stimulate bowel action.
Enemas: a few people, especially those with severe nerve damage in the spine, have to use enemas in which a liquid solution is flushed into the lower bowel to wash it out.
With any laxative, it is important to keep up a good fluid intake – at least four pints of fluid every day and more if possible.
Other treatments
Special tests may show that you have a problem coordinating straining to move the stools while relaxing the exit from the bowel (the anal sphincter). If you have this disorder, you may be helped by training in how to contract your abdominal muscles and relax those around your back passage effectively.
This training can be supplemented by a device that enables you to tell whether your muscle is relaxed (biofeedback – see page 96), but most people don’t need this. Training the muscles is, at present, limited to a few centres, but is likely to become more generally available.
If constipation is associated with emotional problems, counselling or similar treatment may help.
A small number of people require surgical treatment, but this is needed only by those with a definite abnormality of the large intestine.
KEY POINTS
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Changing your diet and developing good bowel habits, together with increased exercise, will be enough for most people to relieve their constipation and control any tendency to gain weight
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Bulkforming or osmotic laxatives are preferable to stimulant laxatives, which should be taken regularly only under medical supervision
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If you are constipated, this does NOT mean that bodily wastes are being absorbed and damaging your health
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If you are over 40 and for no obvious reason have sudden or gradual changes in bowel habit, you should see your GP (especially if you have rectal bleeding or new abdominal symptoms such as distension)