Is a split-dose regimen of 2 L polyethylene glycol plus ascorbic acid tolerable for colonoscopy in an early morning visit to a comprehensive medical check-up?

Table 6 Factors associated with adequate bowel preparation

	Univariate analysis		Multivariate analysis
	HR (95%CI)	P value	HR (95%CI)	P value
Age	0.99 (0.97-1.01)	0.524
Gender (female)	1.26 (0.83-1.91)	0.273
Bowel movement (wk-1)	1.00 (0.94-1.06)	0.989
Low-residue diet (≥ 3 d)	1.55 (1.00-2.39)	0.048	1.49 (0.88-2.53)	0.139
Time of last meal1	3.47 (1.92-6.29)	< 0.001	1.61 (0.78-3.30)	0.195
Type of last meal
Normal or high residue	1.00 (reference)		1.00 (reference)
Rice porridge only	5.09 (1.83-14.12)	0.002	2.26 (0.70-7.30)	0.174
Other low residue2	2.86 (0.94-8.69)	0.064	2.53 (0.72-8.93)	0.150
Preparation regimen (split-dose)	10.63 (6.57-17.19)	< 0.001	10.89 (6.53-18.17)	< 0.001
Intake of PEG/AA (dose)	2.08 (0.20-22.06)	0.543
Intake of water (dose)	0.036 (0.00-12.36)	0.265

¹Whether patients followed recommendations; lunch for non-spilt-dose regimen, dinner for split-dose regimen;

²Other low residue diet includes fish, egg, bread, potato, etc. AA: Ascorbic acid; PEG: Polyethylene glycol.