Constipation

Should I eat plenty of fibre?

In a healthy person, fibre is recommended, as it helps produce normal bowel actions. The fibre is not digested and remains in the bowel; this holds water in the bowel like a sponge (keeping the stools soft), and provides bulk (which gives the muscles of the bowel something to push against to propel the stools through the intestines).

So, if you are eating a fairly normal diet, then plenty of fibre (in fruit, vegetables, cereal etc) is going to help you avoid constipation.

BUT many people with a serious illness have a small appetite, and find that a lot of fibre in their diet makes it unpalatable. They may also find the same is true of medicines containing fibre. Also, even large amounts of fibre are unlikely to counteract the more severe causes of constipation such as painkillers and dehydration.

If this is the case, it is probably better for your quality of life to eat small amounts of foods you enjoy, and use laxatives if and when necessary.

Should I stop my laxatives after my bowels have been loose (diarrhoea)?

Yes AND no. Laxatives usually take many hours, up to several days, to work. There is therefore a ‘lag-time’ between taking laxatives and seeing the effect. If you have had loose motions (diarrhoea), stop the laxatives for the rest of that day (or until the diarrhoea stops). You should normally re-start the laxatives again after a short time - at a lower dose. Do not wait to get constipated again.

Which is the best laxative? (Doctors keep prescribing me different ones.)

There is no reliable evidence to tell doctors or nurses which laxatives are better than others, so there is no right and wrong.

Laxatives generally come in two types: softeners and stimulants. Softeners (eg lactulose, magnesium hydroxide, docusate, Movicol® and Idralax®) make the stools softer and therefore easier to pass. Stimulants (eg senna, bisacodyl) make the bowel contract and push the faeces along the length of the bowel.

For mild constipation, a small dose of almost any laxative seems to work OK. For more severe constipation, most doctors think that a combination of softener and stimulant is the best treatment. Some prescribed medicines contain a mixture (eg co-danthramer and co-danthrusate). There is rarely any point in taking more than two laxatives at a time, but sometimes the doses need to be increased quite a lot.

You may find that you can learn to adjust the dose of laxatives yourself, depending on how soft the faeces are (adjusting the softener), and how difficult you find it to ‘push’ (increasing the stimulant).

Do laxatives have side-effects?

All medicines can have side-effects, but the most common ones to look out for are:

• lactulose - tends to cause gas (or ‘wind’) to build up; this may increase the sense of bloating or abdominal distension
• stimulant laxatives (any) - if they stimulate the muscle of the bowel too strongly they will cause cramping pain, usually called ‘colic’
• co-danthramer and co-danthrusate - can cause the urine to become red (it acts like a harmless dye), which can be mistaken for blood; also occasionally causes a sore rash around the perineum/bottom

I’ve heard that fizzy drinks, tea and coffee may cause constipation - should I stop drinking them?

Caffeine in Coke, Pepsi, tea and coffee acts as a diuretic, and so could lead to mild dehydration if you don’t drink enough other fluids - and dehydration makes constipation more likely.

Some soft drinks have a high sugar content, and this can lead to increased fluid drawn out of the bowel, harder faeces, and therefore constipation.

So, it may be sensible to avoid drinking excessive amounts of these drinks. However, there is no strong evidence that moderate consumption causes problems, and it is probably more important that you drink, than worry too much about what you drink.

I have diarrhoea, but my nurse tells me I am constipated; what is going on?

If someone becomes very constipated, and has a hard (impacted) lump of faeces in the rectum, some of the faeces trying to get past the obstruction will pass as a liquid. This is known as constipation ‘with overflow’. Typically the person will 1) have a history of becoming constipated in the preceding days or weeks, and 2) ‘leak’ small amounts of brown liquid fairly frequently, with little control over the loss.

It is important to diagnose, because obviously the treatment is for constipation, not diarrhoea. Sometimes a rectal examination by the doctor or nurse will be necessary to help confirm what is happening.