Bowel preparation at home: prospective study of adverse effects in elderly people

BMJ 1996; 313 doi: (Published 21 September 1996) Cite this as: BMJ 1996;313:727
  1. T D Heymann, research registrara,
  2. K Chopra, research fellowa,
  3. E Nunn, endoscopy sistera,
  4. L Coulter, endoscopy sisterb,
  5. D Westaby, consultant physiciana,
  6. I M Murray-Lyon, consultant physiciana
  1. a Department of Gastroenterology, Chelsea and Westminster Hospitals, London SW10 9NH,
  2. b Charing Cross Hospital, London W6 8RF
  1. Correspondence to: Dr Westaby.
  • Accepted 18 March 1996

Bowel preparation for colonoscopy may be an unpleasant experience. Increasing pressure on hospital beds effectively precludes inpatient preparation except for the most immobile or infirm patients. Added costs and knowledge that preparation supervised in hospital may be less satisfactory than that done at home1 2 also counsel against inpatient preparation. However, the adverse effects of preparation at home may have hidden costs, and the likelihood of adverse effects may be particularly high in elderly people.

We assessed the adverse effects of bowel preparation at home, and in particular whether elderly people suffer more than younger people.

Patients, methods, and results

In a prospective study consecutive patients undergoing elective colonoscopy in these two hospitals were asked to complete a simple questionnaire designed to elicit adverse affects and overall tolerability of bowel preparation. Allocation of preparation (polyethylene glycol (Klean-Prep, Norgine) or sodium picosulphate (Picolax, Nordic)) was according to hospital and followed local practice. Nine identified side effects were scored 0 to 2 depending on severity; the range of scores was therefore 0 to 18. As appropriate, statistical analysis was performed with the χ2 test, unpaired t test, and Pearson correlation coefficient.

The colonoscopist's satisfaction with the preparation was established by retrospective audit of colonoscopy reports. All patients booked for elective colonoscopy were followed up for three months for serious adverse events from the preparation.

In all, 165 patients were studied, 83 having bowel preparation with sodium picosulphate and the remaining 82 with polyethylene glycol. The response rate was 100%. The mean age of both groups was 60 years (range 25-85 in those given sodium picosulphate and 22-86 in those given polyethylene glycol). The ratio of men to women was similar at both hospitals (0.95 and 0.93). Ten patients (two receiving sodium picosulphate, eight polyethylene glycol; P<0.01) failed to take the full course of preparation. The colonoscopist considered the preparation inadequate in five patients (three receiving sodium picosulphate, two polyethylene glycol; P>0.05), but none of the five had failed to complete bowel preparation. The mean side effect score was 2.9 out of a possible 18 (interquartile range 1-4) in those receiving sodium picosulphate and 3.8 (2-5) in those receiving polyethylene glycol (P<0.001). Sodium picosulphate was rated significantly more favourably than polyethylene glycol (linear analogue score 7.8 (6-10) v 6.3 (4-9); P<0.001).

Faecal incontinence was reported by 22 patients (13%)—10 had received sodium picosulphate, 12 polyethylene glycol (P>0.05). Forty two patients reported sleep disturbance, 21 in each group. No patient required medical intervention such as admission, which was confirmed by follow up of patients who missed their colonoscopy appointments. There was no significant correlation between patients' overall rating of the bowel preparation and age (r = 0.13). However, younger patients complained more often than elderly people of taste disturbance (P<0.01), nausea (P<0.05), fullness (P<0.05), and cramp (P<0.01).

Bowel preparation questionnaire

Please fill in the blanks then circle the replies in the table and finally use the scale from 1 to 10 to give your impression of the overall rating of the bowel preparation

View this table:


Our results suggest that age in itself is not a specific risk factor for adverse effects of bowel preparation. Indeed, young people report specific side effects more often than do elderly people. Perhaps elderly people are more stoical?

Side effects such as sleep disturbance, which may affect patients' partners as well as themselves, and faecal incontinence, which may cause considerable expense, are fairly common and should be considered both by physicians ordering colonoscopies and by economists comparing inpatient and outpatient preparation regimens.

Patients clearly preferred preparation with sodium picosulphate to that with polyethylene glycol. Failure to complete the course was more likely with polyethylene glycol than sodium picosulphate. Polyethylene glycol may give better results,1 3 but as both preparations were satisfactory for colonoscopy we would recommend sodium picosulphate. Significant cost savings (59p v £8.60)4 could result.

Part of these results was used in an oral presentation at the 1995 spring meeting of the British Society of Gastroenterologists and has been published as an abstract in Gut 1996;36(suppl 1):A35.


  • Funding None

  • Conflict of interest None.


  1. 1.
  2. 2.
  3. 3.
  4. 4.
View Abstract