Table 2.

Results of preparation and endoscopic findings

	Standard	Split group
Variable		Day 1	Day 2	P value
No. of patients	78	77
Time to take the solution (min)	115.3 ± 56.7	56.2 ± 23.1	59.1 ± 27.6	<0.001*
Time to first defecation (min, mean±SD)	54.8 ± 34.2	91.1 ± 56.3	47.1 ± 26.2**	0.12*
Frequency of defecation (times, mean±SD)	12.4 ± 4.3	6.8 ± 4.0	10.1 ± 4.7**	<0.01*
Time to preparation (min, mean±SD)	198.1 ± 93.8		175.9 ± 82.9	0.12*
Time to last defecation before going to bed		281.7 ± 83.5
Preparation scale of last defecation (day 1)
(watery clear/clear/muddy/soft stool/normal)		(18/40/14/1/1)
Elapsed time from last fluid intake to	229 ± 115		233 ± 118	0.82*
colonoscopy (min, mean+SD)
Cecal intubation rate (n,%)	78 (100)	77 (100)
Insertion time (min, mean±SD)	8.8 ± 6.0	9.6 ± 5.5		0.41
Feeling of peristalsis (n, %)	15 (19.2)	12 (16.0)		0.60
Optimal visibility grade (0/1/2)	45/24/9	39/19/17		0.17
BBPS (PP)
Right colon (mean±SD)	2.1 ± 1.0	2.1 ± 0.7		0.67
Transverse colon (mean±SD)	2.3 ± 1.0	2.5 ± 0.6		0.12
Left colon (mean±SD)	2.4 ± 1.0	2.6 ± 0.6		0.04
Successful bowel cleansing (n, %)***	65 (83.3)	69 (92.0)		0.10
No. with additional PEG intake or enema (n, %)	9 (11.5)	1 (1.3)		0.01

BBPS: Boston bowel preparation scale

PP: per-protocol analysis

* Same-day group vs. split-dose group (Day 2).

** P<0.001, split-dose group (Day 1) vs. split-dose group (Day 2).

*** Difference and 95% confidence interval in the successful bowel preparation rate between the same-day group and the split-dose group was 8.7% (–1.6% to 19.0%).