Split-dose vs same-day reduced-volume polyethylene glycol electrolyte lavage solution for morning colonoscopy

Table 1 Patient characteristics

Characteristics	Whole-dose same-morning	Split-dose	P
	n = 152	n = 143
Age, yr	61.3 ± 14.9	62.8 ± 13.9	0.378
Male	51.3%	49.0%	0.685
Race
Chinese	56.6%	60.1%	0.434
Malay	21.7%	18.9%
Indian	21.7%	19.6%
Others	0%	1.4%
Education level
None or primary	28.9%	23.8%	0.314
Secondary or higher	71.1%	76.2%
Appointment waiting time
Less than 16 wk	52.6%	48.3%	0.452
16 wk or longer	47.4%	51.7%
Medical condition
Diabetes mellitus	23.7%	19.6%	0.393
Chronic constipation	7.9%	8.4%	0.876
Neurological condition	2.0%	2.8%	0.716
Others	52.6%	55.2%	0.514
Previous abdominal surgery	39.5%	38.5%	0.859
Previous colonic resection	21.1%	13.3%	0.078
Indication
Surveillance	30.3%	32.9%	0.263
Screening	16.4%	27.3%
Altered bowel habit	13.8%	14.0%
Per rectal bleeding	12.5%	9.8%
Abdominal pain	11.2%	6.3%
Anemia	5.3%	3.5%
Chronic diarrhoea	3.9%	1.4%
Chronic constipation	3.3%	3.5%
Others	3.3%	1.4%
Diagnosis
Normal colonoscopy	53.0%	46.5%	0.233
Colonic polyp	23.2%	26.8%
Diverticular disease	9.3%	11.3%
Colorectal carcinoma	4.0%	0.7%
Others	10.6%	14.8%
Seniority of endoscopist
Senior	34.2%	39.9%	0.315
Trainee	65.8%	60.1%

Table 2 Comparison of technical performance of colonoscopy, quality of bowel preparation and patient tolerability between groups

Technical performance	Whole-dose same-morning	Split-dose	P
	n = 152	n = 143
Completed colonoscopy	98.7%	98.6%	1.000
Cecal intubation time, s	600 (432-900)	657 (480-980)	0.510
Withdrawal time, s	298 (180-418)	244 (180-348)	0.235
Total colonoscopy time, s	960 (660-1320)	960 (720-1304)	0.888
Adenoma detection rate	31.6%	30.1%	0.779
Number of adenoma detected	1 (1-2)	2 (1-3)	0.010
Boston bowel preparation scale
Right	2 (2-2)	2 (2-3)	0.060
Transverse	2 (2-3)	2 (2-3)	0.119
Left	2 (2-3)	2 (2-3)	0.176
Total	6 (6-7)	6 (6-8)	0.038
Overall grading of quality of bowel preparation
Good or intermediate	92.1%	97.2%	0.071
Poor	7.9%	2.8%
Completed bowel preparation	94.1%	99.3%	0.020
Difficult to complete bowel preparation	61.2%	29.4%	< 0.001
Will try another preparation	78.9%	53.8%	< 0.001
Refuse the same preparation	13.8%	6.3%	0.033
Barely tolerable or unacceptable taste	7.9%	5.6%	0.432
Nausea	37.5%	25.2%	0.023
Vomiting	16.4%	8.4%	0.037
Abdominal pain	19.7%	13.3%	0.137
Bloating	32.2%	30.1%	0.688
Chest pain	3.9%	5.6%	0.506
Dizziness	10.5%	9.8%	0.834
Level of comfort during bowel preparation
Unfavourable response	28.3%	18.9%	0.058
Favourable response	71.7%	81.1%