Low-volume plus ascorbic acid vs high-volume plus simethicone bowel preparation before colonoscopy

Table 1 Patient demographics, indications and colonoscopy findings

	PEG + Asc	PEG + Sim
ITT patients	72	72
Compliant patients (%)	69 (96)	61 (85)
Cecal intubation (%)	62 (86)	68 (94)
Median age (range)	60.1 (20-84)	57.6 (33-81)
Male (%)	40 (55)	36 (50)
Median timing of colonoscopy (min)	22	21
Indications (%)
Follow-up	27 (37)	18 (25)
Surveillance	8 (11)	11 (15)
CRC sreening	15 (21)	8 (11)
Hematochezia	13 (18)	16 (22)
Change in bowel habits	3 (4)	7 (10)
Anemia	2 (3)	1 (2)
Abdominal pain	4 (6)	11 (15)
Findings (%)
No abnormalities	40 (55)	24 (33)
Diverticular disease	14 (19)	14 (19)
Polyps/Malignancy	13/2 (18/3)	22/0 (31/0)
IBD	1 (2)	3 (4)
Other	2 (3)	9 (13)

ITT: Intention to treat; CRC: Colorectal cancer; IBD: Inflammatory bowel disease; PEG + Asc: Polyethylene glycol plus ascorbic acid; PEG + Sim: Polyethylene glycol plus simethicone.

Table 2 Colonoscopy preparation schedules

PEG + Asc	2 L from 6:00 to 8:00 PM (250 mL every 15 min) plus 500 mL of clear fluid for every L of solution, evening before colonoscopy
	Each liter of PEG + Asc (MoviPrep®) contains 100 g macrogol 3350, 7.5 g sodium sulfate, 2.7 g sodium chloride, 1 g potassium chloride, 4.7 g ascorbic acid, 5.9 g sodium ascorbate, and lemon flavoring
PEG + Sim	2 L from 3:00 to 5:00 PM and 2 L from 6:00 to 8:00 PM (250 mL every 15 min), evening before colonoscopy
	Each liter of PEG + Sim (Selg®-Esse 1000) contains 58.3 g macrogol 4000, 0.08 g simethicone, 5.68 g sodium sulfate, 1.68 g sodium bicarbonate, 1.46 g sodium chloride and 0.74 g potassium chloride and mandarin aroma

A low-fiber diet (mainly the avoidance of fruits and vegetables) was recommended for three days before the endoscopy to all subjects and, the day before, they were advised to have regular breakfast, a light lunch and only clear liquids for dinner. PEG + Asc: Polyethylene glycol plus ascorbic acid; PEG + Sim: Polyethylene glycol plus simethicone.

Table 3 Colonoscopy preparation assessments

Aronchick scale
1 Excellent	Small volume of clear liquid or greater than 95% of surface seen
2 Good	Large volume of clear liquid covering 5% to 25% of surface but greater than 90% of surface seen
3 Fair	Some semi-solid stool that could be suctioned or washed away but greater than 90% of surface seen
4 Poor	Semi-solid stool that could not be suctioned or washed away and less than 90% of surface seen
5 Inadequate	Repreparation needed
Residual stool score (total in sum of three score)
Amount of residual stool	0 = none
	1 = small
	2 = moderate
	3 = large
Consistency of residual stool	0 = none
	1 = clear liquid
	2 = colored liquid
	3 = stool particles
	4 = semi-solid stool
	5 = solid stool
Percent bowel wall visualized	0 ≥ 75%
	1 = 50%-75%
	2 = 25%-49%
	3 ≤ 25%

Table 4 Patient drop-out: global bowel cleansing, side effects and findings

Drop out gut cleansing	PEG + Asc	PEG + Sim
No. of patients	3	11
Global bowel cleansing (%)
Aronchick 1	(1)	(2)
Aronchick 2	(1)	(5)
Aronchick 3	-	(2)
Aronchick 4	(1)	(2)
Aronchick 5	-	-
Cecal Intubation (patients)	2	11
Findings
No abnormalities	1	9
Polyps/malignancy	0/1	2/0
Diverticular disease	1	-
Other	-

PEG + Asc: Polyethylene glycol plus ascorbic acid; PEG + Sim: Polyethylene glycol plus simethicone.

Table 5 Side effects in compliant patients (¹multiple side effects possible)

	PEG + Asc	PEG + Sim
No. of patients	72	72
Side effects patients1	14	21
Nausea	7	16
Vomiting	4	5
Headache	3	1
Insomnia	1	1
Abdominal pain	2	1

PEG + Asc: Polyethylene glycol plus ascorbic acid; PEG + Sim: Polyethylene glycol plus simethicone.

Table 6 Overall gut cleansing and cecal intubation performed

Overall gut cleansing	PEG + Asc	PEG + Sim
No. of patients	69	61
Aronchick 1	8/5	17/16
Aronchick 2	29/27	13/12
Aronchick 3	26/26	24/24
Aronchick 4	5/2	5/5
Aronchick 5	1/0	2/0

PEG + Asc: Polyethylene glycol plus ascorbic acid; PEG + Sim: Polyethylene glycol plus simethicone.

Table 7 Patient questionnaire findings by preparation group tolerability

Question	PEG + Asc	PEG + Sim
Clear liquid at the time of the last evacuation
Yes	51	62
No	21	10
Is this the first time you took a preparation for colonoscopy?
Yes	33	43
No	39	29
Discomfort:
None	18	28
Slightest	32	36
Moderate	17	6
Severe	5	2
How much would you be prepared to repeat this preparation for colonoscopy?
A little	18	15
Fairly	32	42
Much	15	11
I would never repeat	7	4

PEG + Asc: Polyethylene glycol plus ascorbic acid; PEG + Sim: Polyethylene glycol plus simethicone.