Table 2.

Comparison of two-man method vs one-man sitting method vs one-man standing method

	Two-man method	One-man standing method	One-man sitting method
The proportion of colonoscopists using methods	A few	Most	A few (More than two-man method)
Minimal number of assistants	Two people	One person	One person
Space	Relatively large	The smallest	Small
Colonoscope	Only long length adult-colonoscope	Both long length- and intermediate length- adult colonoscope (Intermediate-scope preferred)	Both long length- and intermediate length- adult colonoscope (Intermediate-scope preferred)
The role of colonoscopist	Only manipulation of the control section of colonoscope; most manipulations of colonoscope such as advance (push-forward) and withdrawal (pull-back) by assistant	All manipulations of colonoscope including advance, withdrawal, and handling of the control section	All manipulations of colonoscope including advance, withdrawal, and handling of the control section
The fatigue of colonoscopist	Low	High	Lowest
Location of examinee's anus	Below examiner's head	Below examiner's head	Examiner's head level (colonoscopist may be required to wear a mask for hygiene reasons)
The risk of perforation	Relatively high (colonoscopist cannot feel the colonoscope insertion)	Relatively low (colonoscopist can feel the colonoscope insertion)	Relatively low (colonoscopist can feel the colonoscope insertion)