Constipation

Overview

The normal frequency of bowel movements varies widely, from three a day to three a week. What is normal for one person may not be normal for someone else. In general constipation is characterized by a decreased frequency of bowel movements and the passage of dry, hard stools less than three times a week.

How we get constipation

Normally, the waste products of digestion are propelled through the intestines by muscle contractions. In the large intestine, most of the water and salt in this mixture is reabsorbed because they are essential for many of the body’s functions. If too much water is absorbed or if the waste moves too slowly it may result in constipation.

Symptoms

Changes in bowel habit and stools

The “normal” range for bowel movements varies from individual to individual, with some passing stools, once a day and others passing stools three times a week.  Constipation for an individual is therefore when the passing of stools is less frequent than normal and the stools are hard, small and difficult to pass.

Abdominal discomfort and bloating

Constipation is often associated with abdominal discomfort, bloating and nausea.

Haemorrhoids

Constipation and prolonged straining when using the toilet are thought to contribute to the formation of haemorrhoids by increasing the pressure in the
veins.  Haemorrhoids are small, blood-filled swellings caused by dilated varicose veins. Initially, they are located just inside the anus (internal haemorrhoids) but can sometimes protrude (external haemorrhoids).

Blood on defaecation

Haemorrhoids and fissures (cracks in the anal skin), are both caused by the straining and passage of hard, dry, stools, which are both associated with
constipation.  Both haemorrhoids and fissures bleed, but the blood seen is fresh (bright red) and generally in small quantities, on the stool and/or toilet paper.

Risk Factors

Diet

The most common cause of constipation is a diet low in fibre and high in fats.

Fibre is both soluble and insoluble and is part of fruits, vegetables, and grains that the body cannot digest. Soluble fibre dissolves easily in water and takes on a soft, gel-like texture in the bowel. Insoluble fibre passes through the bowel almost unchanged. The bulk and soft texture of fibre help prevent hard, dry stools that are difficult to pass.

Fluid intake

Another common cause of constipation is failure to drink enough clear liquids or fruit juice.

Liquids like water and juice add fluid to the colon and bulk to stools, making bowel movements softer and easier to pass.

Age

Sometimes young children are constipated because they forget to take time to use the toilet. Toddlers may become constipated during toilet training if they are afraid or unwilling to use the toilet. Children may also experience constipation as a direct result of a poor diet, high in processed foods, or a refusal to eat fruit and vegetables and an inadequate fluid intake.

Elderly people often become disinterested in food and find many foods hard to chew and swallow. This can result in their consumption of processed foods. The elderly also commonly do not drink enough clear fluids or juice. Elderly people are also less likely to be physically active and those on medication may be constipated as a result of the drugs they are taking.

Lack of exercise

Lack of exercise can lead to constipation, although doctors do not know precisely why. Constipation often occurs after an accident or during an illness when an individual is confined to bed and cannot exercise.

Pregnancy

Constipation is common in pregnancy and is a result of changes in hormone levels. Oral iron often taken by pregnant women can also contribute to the
problem.

Medication

Some prescribed and over-the counter drugs can cause constipation. They include pain killers (particularly those containing opiates, such as codeine), antacids containing aluminium, certain blood pressure medication (calcium channel blockers and diuretics), drugs used to treat Parkinson’s disease, some drugs used to treat depression and epilepsy and iron supplements.

Irritable bowel syndrome (IBS)

Some people with IBS, also known as spastic colon, have spasms in the colon that affect bowel movements. Constipation and diarrhoea often alternate and abdominal cramping, gassiness and bloating are other common complaints. Although IBS can produce lifelong symptoms, it is not a life-threatening condition. It often worsens with stress, but there is no specific cause or anything unusual that the doctor can see in the colon.

Changes in routine

People often become constipated when travelling because their normal diet and daily routines are disrupted.

Abuse of stimulant laxatives

Laxatives may be abused by those who are obsessed with daily bowel movements (most commonly seen in the elderly) or by those who take laxatives in the belief that they will control weight. This may be individuals who are dieting or those with eating disorders, such as anorexia nervosa or bulimia.

The abuse of stimulant laxative can lead to long-term constipation. This is because the colon begins to rely on laxatives to bring on bowel movements. Over time, laxatives can damage nerve cells in the colon and interfere with the colon’s natural ability to contract, this then leads to the requirement to take more and more stimulant laxatives in order to cause a bowel movement and the inability of the colon to contract and expel stools naturally.

Ignoring the urge to move the bowel

People who ignore the urge to have a bowel movement may eventually stop feeling the urge, which can lead to constipation. This may be as a result of not wanting to use toilets outside the home, a hectic lifestyle or emotional stress.

Intestinal blockage

Blockage of the intestines may be caused by tumours, hernias, scar tissue, hardened faeces, gallstones, and foreign bodies, twists in the bowel or infection in the bowel. The symptoms of an intestinal blockage may be abdominal swelling, nausea and vomiting (often of faecal matter) and sometimes total constipation for a number of days or even weeks.

Other disease states

Diseases that cause constipation include diseases that affect the nervous system, such as stroke, multiple sclerosis, Parkinson’s disease and spinal cord injuries. Diseases that affect the metabolism such as diabetes or a under or overactive thyroid gland and other serious illnesses affecting the body’s organs. These disorders can slow the movement of stool through the colon, rectum, or anus.

Complications

Constipation leads to the formation of hard, dry stools and straining to expel these along with their degree of hardness can lead to haemorrhoids and cracks and tears in the anus, called abrasions or fissures.

Very severe or chronic constipation can sometimes cause a faecal impaction, a mass of hardened stool that cannot be eliminated by a normal bowel movement. An impaction can be dangerous, and may need to be manually removed by a nurse or doctor.

The long-term abuse of stimulant laxatives can not only lead to long-term constipation (as discussed above in Risk factors) but can also lead to deficiency syndromes due to the limited absorption of vitamins and other nutrients in the bowel.

When to seek medical advice

It is important to consult a doctor when there is a recent, unexplained onset of constipation or change in bowel habits, or any of the following signs or symptoms, which might indicate a more serious health condition:

  • Failure of one or more laxatives to treat symptoms
  • Bowel movements just once or twice a week, despite corrective changes in diet or exercise
  • Intense abdominal pain
  • Blood in your stool
  • Constipation that alternates with diarrhoea
  • Rectal pain
  • Thin, pencil-like stools
  • Unexplained weight loss

Treatment

Constipation that is not a result of any serious illness can normally be rectified by increasing dietary fibre and liquid intake and taking regular exercise (see Prevention). In the short-term laxatives may help ease the immediate problem.

There are four different groups of laxatives, that give relief to constipation in different ways. Your pharmacist can recommend one that is most suitable for you, especially if is necessary for you to take laxatives on a long-term basis.

Many over-the-counter preparations are not suitable for those who are pregnant or for children under two years of age and may not be suitable for other individuals, so it is always important to talk to your pharmacist when buying preparation for constipation over-the-counter.

Stimulant laxatives (e.g. senna, bisacodyl and sodium picosulphate)

These laxatives are available in liquid, tablet and suppository form.

These work by increasing the muscular contraction of the bowel and because of this cause cramping and griping pain. It is advisable to start at the lower end of the recommended dosage range, increasing the dose if required, as the intensity of the laxative effect is related to the dose taken. Oral stimulant laxatives should be taken at night as they work within six to twelve hours and bowel evacuation, along with griping and cramping pain, will then occur in the morning. When used in suppository form stimulant laxatives will normally cause bowel evacuation within an hour.

Castor oil is also a stimulant laxative and a traditional remedy for constipation. It is best taken on an empty stomach and has an unpleasant taste. It also causes griping pain and is not a product that should be recommended when there are much more effective alternatives, with less side-effects.

Because continual use of stimulant laxatives can cause significant long-term problems with the bowel, their use is only recommended as a “quick fix” for constipation. They may be used occasionally and for up to one week only.

Bulk laxatives (e.g. ispaghula, methylcellulose, sterculia)

These laxatives are available in powder (sachet or drum) form and are diluted in water to give a solution.

Bulk laxatives most closely copy the normal functions involved in bowel evacuation. They do not cause pain and have no long-term side-effects so are therefore the safest laxatives, particularly where changes in diet and exercise have failed to help constipation and a laxative is recommended for continual use.

They work by swelling in the gut and increasing the size of the faeces, so that the muscular contractions of the bowel are stimulated. It is important that the sachets or recommended quantity of powder is dissolved in a full glass of liquid (fruit juice or water); as such preparations can cause blockages in the bowel if inadequate fluid is taken with them.

The laxative effect of these products can take several days to develop, so they are generally used in cases of frequent and long-term constipation, in those groups of people that are at risk of being constipated regularly.

Lubricant laxatives (e.g. liquid paraffin)

Liquid paraffin works by coating and softening the faeces and it prevents further absorption into the faeces, from the bowel.

Long-term use of liquid paraffin can lead to deficiency syndromes as it impairs the absorption of vitamins that normally enter the body through the absorption of fat (vitamins A, D, E and K). Leakage of liquid paraffin through the anal sphincter may also occur, causing embarrassment and unpleasantness. Inhalation of liquid paraffin by vomiting or acid reflux may lead to pneumonia.

Because of the many side-effects of liquid paraffin and the availability of much more effective and safer alternatives, its use cannot be recommended in constipation.

Osmotic laxatives (e.g. lactulose, glycerin/glycerol, phosphate and sodium salts, Epsom salts)

These are available in liquid powder and enema form.

Epsom salts work by drawing water into the bowel which softens the faeces and their increased size stimulates the bowel to move. Epsom salts cause bowel evacuation in a few hours and are therefore suitable for occasional use for infrequent bouts of constipation. Their long-term is not recommended, as they can lead to dehydration.

Lactulose is not absorbed from the gastro-intestinal tract and so draws water in (by osmosis) to produce more watery stools thus relieving constipation. The effects of lactulose may take one to two days to develop. Lactulose appears to be a safe long-term treatment for constipation and some find it more palatable than bulk laxatives. It should, however, be avoided by diabetics, in whom it would increase blood sugar.

Glycerin/glycerol suppositories have both osmotic and irritant effects and usually act within an hour of insertion into the rectal passage. They may cause
rectal discomfort, but are a useful remedy for infrequent and occasional bouts of constipation.

Phosphate and sodium citrate enemas usually act within an hour of insertion into the rectal passage. They are again a useful remedy for infrequent and occasional bouts of
constipation.

Brand name of preparations available and their ingredients

Stimulant laxatives

Castor Oil

Laxoberol syrup contains sodium picosulphate.

Senokot tablets, syrup and contain senna.

Dulcolax tablets, pearles, and suppositories contain bisacodyl.

Toilax micro-enema contains bisacodyl.

These products are recommended for occasional use. They tablet and syrup forms cause griping pain before bowel evacuation and this can be uncomfortable and unpleasant. The suppository and enema forms provide quick relief (normally within an hour) from constipation and therefore can be useful without too much discomfort in occasional constipation. They do not cause drowsiness.

Bulk laxatives

Fybogel sachets and powder contain ispaghula husk.

Normacol sachets and granules contain sterculia.

These products are very safe for (even in pregnancy) and are the recommended medication for regular or long-term constipation. They should be used on a daily basis to promote regular bowel evacuation. When taken they should be dissolved in plenty of water. It is also recommended that they are not taken just before bedtime. They do not cause drowsiness.

Lubricant laxatives

Liquid Paraffin is a product that is no longer recommended for constipation.

Osmotic laxatives

Mik of Magnesia liquid contains magnesium hydroxide

Glycerol/glycerin suppositories

Microlax enemas contain sodium citrate, sodium lauryl sulphoacetate, sorbitol, glycerol and sorbic acid.

Lactulose syrup

Epsom salts

The liquid and powders in this group i.e. lactulose syrup, milk of magnesia and Epsom salts help to draw water into the stool and so relieve constipation. Epsom salts and Milk of Magnesia’s use long-term can lead to dehydration, but lactulose is safe long-term and therefore is recommended in frequent or long-term constipation (except in diabetics due to the sugar content of the syrup) and in this case it should be taken every day to promote regular bowel evacuation.

The suppositories and micro-enemas, such as glycerin/glycerol suppositories and Microlax enemas are useful to relieve occasional bouts of constipation and are usually effective within an hour of use.

None of these products cause drowsiness.

Products with mixed ingredients

Milpar liquid contains osmotic laxatives magnesium hydroxide and sodium hydrogen carbonate and lubricant laxative liquid paraffin. Due to the inclusion of liquid paraffin in this product it should only be used to relieve occasional constipation.

Prevention

Change your diet

The amount of high fibre foods in the diet must be increased to help avoid constipation. High fibre foods include beans, whole grains and bran cereals, fresh fruits, and vegetables. For people prone to constipation, limiting foods that have little or no fibre, such as ice cream, cheese, meat, and processed foods, is also important.

Increase fluid intake

Adequate fluid intake (eight to ten cups a day or two litres) is also important in preventing constipation. Fluids other than water (such as fruit juices) are acceptable but, sugary fizzy drinks are not recommended. Try not to drink liquids that contain caffeine or alcohol, as they tend to dry out your digestive system.

Take regular exercise

Regular exercise helps your digestive system stay active and healthy; in general a twenty to thirty minute walk every day is beneficial in many ways to your health.

Take time to move your bowel

Do not ignore the urge to move your bowel and allow yourself adequate time in the toilet to completely empty your bowel.

Self-Care

If you suffer from frequent bouts of constipation it is important to follow the preventative measures above. When faced with constipation when your bowels are normally very regular, also try following the advice above. If you stimulate the bowel enough, contractions will help get the hardened stool out. Try prunes or other fruits and take moderate exercise.