Colonoscopy procedural skills and training for new beginners

Table 1 Comparison of endoscopes: Adult-gastroscope vs intermediate length adult-colonoscope vs long length adult-colonoscope

Characteristic	Adult-gastroscope	Adult-colonoscope
		Intermediate length-type	Long length-type
Total length1	1350 mm (1.35 m)	1650 mm (1.65 m)	2000 mm (2 m)
Working length2	1030 mm (1.03 m)	1330 mm (1.33 m)	1680 mm (1.68 m)
Diameter	9.2 mm	12.9 mm
Diameter of instrument channel	2.8 mm	3.7 mm
Angulation range3	Up 210°, Down 90°, Right 100°, Left 100°	Up 180°, Down 180°, Right 160°, Left 160°

¹Total length is defined as the maximal length of the scope’s insertion;

²Working length is defined as the graduated length;

³The tip of scope, i.e., bending section, was angulated by the scope’s control knob.

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)