Ascorbic acid and low-volume polyethylene glycol for bowel preparation prior to colonoscopy: A meta-analysis

Table 1 Details of studies included in the meta-analysis

Author	Type of study	Blinding	Location	No. of patients	Low-volume bowel preparation	Full-dose bowel preparation	Jadad Score
Clark et al[27] 2007	RCT Abstract	Single	Not specified	294	2 L PEG with ascorbic acid	4 L PEG	1
Ell et al[24] 2008	RCT	Single	Germany	308	2 L PEG with ascorbic acid	4 L PEG	3
Lee et al[26] 2008	RCT Abstract	Single	Not specified	56	2 L PEG with ascorbic acid	4 L PEG	1
Corporaal et al[22] 2010	RCT	Single	Netherlands	307	2 L PEG with ascorbic acid	4 L PEG	2
Marmo et al[23] 2010	RCT	Single	Italy	433	2 L PEG with ascorbic acid	4 L PEG	3
Pontone et al[19] 2011	RCT	Single	Italy	130	2 L PEG with ascorbic acid	4 L PEG with Simethicone	3
Jansen et al[21] 2011	RCT	Single	Netherlands	370	2 L PEG with ascorbic acid +/- Simethicone	4 L PEG +/- Simethicone	3
González-Méndez et al[25] 2011	RCT Abstract	Single	Spain	681	2 L PEG with ascorbic acid + Bisacodyl	3 L PEG + Bisacodyl	1
Valiante et al[20] 2012	RCT	Single	Italy	332	2 L PEG with ascorbic acid	4 L PEG	3

PEG: Polyethylene glycol; RCT: Randomized controlled trial.

Table 2 Outcomes of side effects analyzed between low-volume polyethylene glycol with ascorbic acid and full-dose polyethylene glycol before colonoscopy

Side effect	OR	95%CI	P-value	Significance
Abdominal pain	1.09	0.81-1.48	0.56	NS
Nausea	0.70	0.49-1.00	0.05	NS
Vomiting	0.99	0.78-1.26	0.95	NS

NS: Not significant.