Cheaper laxatives just 'as effective'

Foods rich in fibre can help treat constipation

Cheap laxatives are just as effective as more expensive alternatives in treating constipation, researchers have found.

The NHS Centre for Reviews evaluated all the research carried out into their use.

Laxatives cost the NHS in England £46m per year.

Around 20% of older people living in the community are affected by constipation. It is even more common amongst those living in nursing homes.

How costs vary (per day)

Bran (bulk-forming) - £0.12 - £0.18

Senna (stimulant) - £0.03 - £0.06

Arachis oil (faecal softener) - £1.02

Macrogals (osmotic) - £0.74 - £1.11

The NHS CRD found there was no difference in effectiveness between the four main types of laxatives, despite some being more expensive than others.

One unnamed expert said it was right to choose cheaper options, but said doctors should have each of the four types available so they could be sure the most suitable kind of laxative was available for each patient.

In its review, carried out at the behest of the National Institute for Clinical Excellence, the NHS CRD said a "stepped approach" is recommended, starting treatment with cheaper laxatives, moving on to more expensive alternatives if needed.

In its Effective Health Care bulletin, which is sent to GPs and other health experts, the NHS CRD suggests mild constipation should be treated by increasing the amount of fibre in the patient's diet.

It adds that more severe constipation could require treatment with laxatives, once any underlying disease has been excluded.

Bowel actions

A person is deemed to be constipated if they have fewer than three bowel actions in a week, or if there is often a need to strain to pass a stool.

It can be caused by a lack of fibre, or roughage in the diet, if the need to go to the toilet is ignored, or if they fail to use their muscles effectively as they strain.

Laxatives work by increasing bowel movement frequency and improving the symptoms of constipation.

There are four main types:

• Bulking agents, such as bran. These increase the amount of fibre in the diet, and increase the weight and water-absorbent properties of the stool
• Stimulant laxatives, such as senna
• Faecal softeners, such as liquid paraffin. The use of this kind of laxative should be discouraged, says the NHS CRD, because of its adverse effects including anal seepage
• Osmotic, such as lactulose, which also act by softening and increasing water absorption in the stool.

Costs varied within each category.

Alison Booth, research fellow for the Centre, told BBC News Online: "There is much uncertainty over what constitutes effective management of constipation and laxatives may not be appropriate in all patients suffering from this problem.

"The CRD study highlights the need for further research into the management of constipation.

"In the meantime, we hope that the findings of this study will inform the decisions made by doctors and other health professionals when prescribing laxatives."

Mr Roger Leicester, a bowel surgeon at London's St George's Hospital and spokesman for the Digestive Disorders Foundation, said cheaper laxatives were as effective as more expensive ones and should be tried first.

But he said doctors should still have the choice of the four main types: "Different laxatives are used in different ways for different people."