Improvement in caecal intubation rate and pain reduction by using 3-dimensional magnetic imaging for unsedated colonoscopy: a randomized trial of patients referred for colonoscopy

Scand J Gastroenterol. 2007 Jul;42(7):885-9. doi: 10.1080/00365520601127125.


Objective: Use of magnetic endoscope imaging (MEI) during colonoscopy has the potential to ease caecal intubation and patient discomfort and to reduce dependence on sedation and/or analgesics (SAs). However, pain reduction by using MEI has not been demonstrated so far, probably because of the liberal use of SAs. The aim of the present study was to evaluate the effect of MEI on caecal intubation and patient pain during unsedated colonoscopy performed by experienced and inexperienced colonoscopists.

Material and methods: A consecutive series of outpatients referred for colonoscopy were randomly allocated to examination with (imager group) or without (standard group) the use of MEI. Patients agreeing to SAs being given only on demand were included in the study. End-points were caecal intubation and pain, the latter to be graded by category on a form to be completed on the day after the examination.

Results: The proportion of colonoscopies performed without SAs was similar when comparing imager and standard groups and experienced with inexperienced colonoscopists; altogether 367(88%) out of 419 colonoscopies. The caecal intubation rate was higher in the imager group (190/212 (90%)) than in the standard group (153/207(74%)) (p<0.001), both collectively and separately for experienced and inexperienced colonoscopists. A pain-reducing effect of MEI was shown only when performed by experienced colonoscopists, with severe pain in 10/137 patients (7.3%) in the imager group and 21/132 patients (16%) in the standard group (p=0.03).

Conclusions: In colonoscopy without the routine use of SAs, MEI significantly improves the caecum intubation rate and reduces pain during the procedure.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Analgesics / therapeutic use
  • Cecum
  • Clinical Competence
  • Colonoscopy / adverse effects
  • Colonoscopy / methods*
  • Female
  • Humans
  • Hypnotics and Sedatives / therapeutic use
  • Imaging, Three-Dimensional / instrumentation*
  • Intubation, Gastrointestinal / adverse effects
  • Intubation, Gastrointestinal / methods*
  • Magnetic Resonance Imaging*
  • Male
  • Middle Aged
  • Pain / drug therapy
  • Pain / etiology
  • Pain Measurement


  • Analgesics
  • Hypnotics and Sedatives