Is the variable-stiffness paediatric colonoscope more effective than a standard adult colonoscope for outpatient adult colonoscopy?: A randomised controlled trial

BACKGROUND: Trials with variable-stiffness colonoscopes have yielded conflicting results regarding efficacy and patient tolerance. AIM: We compared a variable-stiffness paediatric colonoscope with a standard adult colonoscope. METHODS: Two hundred and forty consecutive adult outpatients presenting for colonoscopy were randomised to either a variable-stiffness paediatric colonoscope or an adult colonoscope. If there was difficulty in performing colonoscopy with the assigned scope, the endoscopist was given the option of switching to the alternative instrument. In the condition of a severely fixed, angulated sigmoid colon, a final 'salvage' (backup) option was that of switching to an even thinner diameter paediatric colonoscope. RESULTS: The initial frequency of total colonoscopy was similar with the variable-stiffness paediatric colonoscope and adult colonoscope (95.8% versus 96.6%, p=1.0). Factoring in scope changes, the final frequency was 98.3% versus 99.2% (p=1.0). There was no statistical difference between the two groups in terms of insertion time, doses of sedative medications, scales of procedure difficulty, or patient satisfaction. CONCLUSIONS: Adult colonoscope and variable-stiffness paediatric colonoscope are both effective instruments for routine colonoscopy. In cases when the use of the initial scope is unsuccessful, switching to the alternative scope may permit passage to the caecum. There are occasional patients with fixed, angulated sigmoid colons in whom use of an even thinner diameter paediatric colonoscope can be helpful.