Twenty one Shropshire practices took part in a retrospective audit of prescribing of stimulant laxatives. Each practice counted the number of patients having repeat prescriptions for stimulant laxatives and then reviewed the notes of ten of those patients. Prescribing rates varied from 0.1% of the practice population to 4.17% with nine practices prescribing regularly for children under sixteen years of age. Some practices are now reviewing their policy on stimulant laxative prescribing and one has made major changes in the care of nursing home residents.
Constipation is perceived by many people to be a chronic problem and the prescribing of laxatives is a major expense for the NHS with prescriptions for laxatives amounting to approximately 400,000 per year. (1)
Bowel habit can vary considerably in frequency without the patient suffering any harm and people need to be educated to understand this. Misunderstanding of the nature of normal bowel function can lead to the excessive use of stimulant laxatives with the risk of metabolic problems and an atonic, non-functioning colon.(2) Laxative use can occasionally mask the symptoms of more serious disease such as bowel neoplasia.

The idea to use stimulant laxative prescribing as a topic for a collaborative audit was suggested to PCAG by the results of an audit carried out by one Shropshire practice. A recent edition of Bandolier noted the lack of good clinical trials into the outcomes of laxative prescribing.(3)
To investigate the extent of stimulant laxative prescribing in 21 practices in Shropshire.
  1. All patients should have the reason for prescribing laxatives recorded.
  2. Patients should have been examined at least once since starting treatment.
  3. If a rectal examination is performed the results should be recorded.
  4. All patients should be reviewed annually.
  5. All patients should receive advice on avoidance of the causes of constipation, dietary measures and the alternatives to stimulant laxatives.
  6. Patients should be educated to report episodes of rectal bleeding and alterations in bowel habit.

No numerical standards were set in view of the lack of evidence on good practice in this area.
Practices were asked to use their computers to search for repeat prescriptions within the BNF group 1:6:2, the stimulant laxative section. From this information they were requested to:
  1. Record the total number of patients receiving repeat prescriptions for stimulant laxatives.
  2. Randomly select 10 patients for more in depth inquiry ( Or total if less than 10)
  3. Scrutinise the 10 sets of notes or computer records for recording of the criteria and record answers on the data collection sheets.
  4. Return data collection sheets to PCAG.
21 practices agreed to take part in the audit. 1302 patients were discovered to be taking stimulant laxatives an average prescribing rate of 0.76% for the population of 170,479 patients. The range of patient numbers varied from <10 to over 300. Prescribing rates per practice varied from 0.1% to 4.17%.

A random sample of 201 patients was selected. 63% of the patients are female, 37% male. The proportion of females to males is 2:1 in all age groups except children where there were twice as many boys as girls.

2% of patients have been on treatment for more than 10 years and 60% of patients were first prescribed the laxative since 1995.

135 patients, 65.7%, had the reason for the laxative prescription recorded in their notes or on computer. The commonest reasons for treatment were:
Diverticular disease
Analgesia including terminal care
Spinal problems
Other including pre-op, renal failure, abdominal pain

141 patients, 70%, had been examined since the prescribing of the laxatives started. Only 29% were recorded as having had a rectal examination.
72.1%, 145 patients, had had their medication reviewed in the last year.
64 people were recorded as having been advised about other methods of relieving constipation rather than stimulant laxatives and 15.4%, 31 patients, had been told what to do in the event of a rectal bleed or a change in bowel habit.
Prescribing for children
12 children under the age of 16 years were identified as being on repeat laxative prescribing, four girls and eight boys. All but one had been given a senna product and three were also on lactulose. The remaining child, a four year old girl has been taking sodium picosulphate since 1995.
The children had been on medication for an average of 3.8 years with a range of 1-6 years. All the children had prescriptions for constipation although one child also has a spinal disorder.

It is undoubtedly better for patients to understand and control their bowel actions without the use of stimulant laxatives if at all possible. A number of recommendations can be made from this audit:
  1. Where laxatives are necessary there is evidence that bulk forming ones give better results than other types.(3)
  2. Practices with high prescribing rates for stimulant laxatives should look at their prescribing in more detail.( The sample size of 10 patients is not likely to give significant indication of any problems within the practice.)
  3. Practices prescribing for children should review those patients who have been on stimulant laxatives for more than a short while.
  4. New prescriptions should be for a short term only especially for children.
  5. Examination details should be recorded more carefully.
  6. All patients should receive dietary and life style advice and this should be recorded in the notes.
  7. All patients should be aware of sinister symptoms of bowel disease and what to do about them.

Most of the practice who collaborated with this audit have prescribing rates for stimulant laxatives of < 1% of the practice population. Approximately two thirds of the patients had a reason for prescribing recorded, had been examined in the last year and had a recent review of their treatment.
Recording of dietary advice and warning signs of more serious diseases is much less common as is whether or not a rectal examination had been performed.
Bowel neoplasia are common and, as 88% of the patients in this study are aged forty years or over, more evidence of patient education on abnormal bowel habit and rectal bleeding needs to be recorded in the notes.
The analysis of the children taking long term treatment for constipation is also worrying. Although they represent only 0.6% of the cohort from nine practices it is of some concern that a number of children have been taking senna products for several years.

This audit was collated by Shropshire Primary Care Audit Group and the results fed back to participating practices. Several practices have since expressed an interest in looking at their prescribing of laxatives in more detail and those with high prescribing rates for children are reviewing the patients. Some practices will be performing a repeat audit. The practice with the highest prescribing rate was informed that it was top of the league. A subsequent investigation by the practice revealed some poor nursing home practices. The residents in two nursing homes on their patch appeared on detailed investigation to be having diets inadequate in fibre, little or no exercise and in many cases to have been unnecessarily catheterised. The practice has exerted influence on these homes to improve the care of their residents and has instituted repeat prescribing systems that will prevent a recurrence of the over-prescribing. They will repeat the audit in a year to make sure the changes continue to work.

  1. Harris C, Heywood P and Clayden AD Analysis of Prescribing in General Practice, page 41
  2. British National Formulary Section 1.6.2
  3. Bandolier Vol 4:12:4