Table 1. Main outcome: Subjects and clinical characteristics.

Subjects	n = 880
Ages (years)			57.9±11.6 (29–88)
Gender		male	n = 608	69.1%
		female	n = 272	30.9%
Past abdominal operation		yes	n = 184	20.9%
		no	n = 696	79.1%
		no	n = 372	42.3%
Previous examination		yes	n = 508	57.7%
Colonoscopy	n = 880
Bowel preparation quality	n = 806	excellent, good, fair	n = 785	97.4%
		poor	n = 21	2.6%
		inadequate	n = 0	0%
Sedation practice	n = 880	opiate	n = 657	74.7%
		benzodiazepine	n = 3	0.3%
		both	n = 202	23.0%
		none	n = 18	2.0%
Presence of Diverticulosis	n = 880	yes	n = 265	30.1%
		no	n = 615	69.9%
Insertion difficulty	n = 806	easy	n = 610	75.7%
evaluated by endoscopist		slight difficult, difficult	n = 196	24.3%
		impossible	n = 0	0%
Pain evaluated by	n = 800	none	n = 670	83.7%
endoscopist		weak	n = 111	13.9%
		strong	n = 19	2.4%
Insertion time (min)	n = 607		6.4±4.0 (1–40)
Withdrawal time (min)	n = 878		5.5±2.0 (1–23)