AIM:To evaluate whether an endoscopy position detecting unit(UPD-3) can improve cecal intubation rates, cecal intubation times and visual analog scale(VAS) pain scores, regardless of the colonoscopist’s level of experience.METHODS:A total of 260 patients(170 men and 90women)who underwent a colonoscopy were divided into the UPD-3-guided group or the conventional group(no UPD-3 guidance).Colonoscopies were performed by experts(experience of more than 1000colonoscopies)or trainees(experience of less than 100colonoscopies).Cecal intubation rates,cecal intubation times,insertion methods(straight insertion:shortening the colonic fold through the bending technique;roping insertion:right turn shortening technique)and patient discomfort were assessed.Patient discomfort during the endoscope insertion was scored by the VAS that was divided into 6 degrees of pain.RESULTS:The cecum intubation rates,cecal intubation times,number of cecal intubations that were performed in<15 min and insertion methods were not significantly different between the conventional group and the UPD-3-guided group.The number of patients who experienced pain during the insertion was markedly less in the UPD-3-guided group than in the conventional group.Univariate and multivariate analysis showed that the following factors were associated with lower VAS pain scores during endoscope insertion:insertion method(straight insertion)and UPD-3guidance in the trainee group.For the experts group,univariate analysis showed that only the insertion method(straight insertion)was associated with lower VAS pain scores.CONCLUSION:Although UPD-3 guidance did not shorten intubation times,it resulted in less patient painduring endoscope insertion compared with conventional endoscopy for the procedures performed by trainees. AIM: To evaluate whether an endoscopy position detecting unit (UPD-3) can improve cecal intubation rates, cecal intubation times and visual analog scale (VAS) pain scores, regardless of the colonoscopist’s level of experience. METHODS: A total of 260 patients ( 170 men and 90 women) who underwent a colonoscopy were divided into the UPD-3-guided group or the conventional group (no UPD-3 guidance). Colonoscopies were performed by experts (experience of more than 1000 colonsoscopies) or trainees (experience of less than than 100colonoscopies) .Cecal intubation rates, cecal intubation times, insertion methods (straight insertion: shortening the colonic fold through the bending technique; roping insertion: right turn shortening technique) and patient discomfort were assessed. Patient discomfort during the endoscope insertion was scored by the VAS that was divided into 6 degrees of pain .RESULTS: The cecum intubation rates, cecal intubation times, number of cecal intubations that were performed in <15 min and insertion method the number of patients who experienced pain during the insertion was markedly less in the UPD-3-guided group than in the conventional group. Univariate and multivariate analysis showed that the following factors were associated with lower VAS pain scores during endoscope insertion: insertion method (straight insertion) and UPD-3 guidance in the trainee group. For the experts group, univariate analysis showed that only only insertion method was associated with lower VAS pain scores. CONCLUSION: Although UPD-3 guidance did not shorten intubation times, it resulted in less patient painduring endoscope insertion compared with conventional endoscopy for the procedures performed by trainees.