Two measures of benefit were used:
(1) the adequacy of bowel preparation as rated by a colonoscopist, in a retrospective audit of colonoscopy reports, and
(2) tolerability as reported by patients.
The tolerability estimates were obtained by means of a questionnaire asking patients to rate nine side effects from a scale of zero to 2 each (maximum achievable severity, 18), and by an overall favourability rating on a visual analogue scale.