Effectiveness of Oral Sodium Phosphate Bowel Preparation for Colonoscopy: A Meta-Analysis

Friday, 28 July 2017

Hsin-Mei Ho, MSN1
Yueh-Yen Fang, PhD2
Shu-Chi Chen, MSN1
Chin-Han Hsieh, BSN1
(1)Department of Nursing, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
(2)School of Nursing, Fooyin University, Kaohsiung, Taiwan


Colon cancer is one of the top ten causes of death, and colonoscopy is one of the most commonly used diagnostic procedures. Effectiveness of bowel preparation is significant for the success of colonoscopy. The type and severity of bowel preparation side effects vary with the product used. Common adverse effects include nausea, vomiting, bloating, or abdominal pain. For the severe cases, kidney failure, heart failure or seizures might present. Though polyethylene glycol (PEG) is isotonic, the large volume used for bowel preparation and adverse events of nausea and abdominal discomfort may compromise patient compliance and increase the need for repeat procedures. Sodium phosphate (NaP) is used as an alternative for bowel preparation in current days. However, studies that compare the effects of bowel preparation between NaP and PEG are inconsistent. To validate the effect of NaP on bowel preparation for colonoscopy, this study compared the efficiency and adverse events of NaP and PEG bowel preparations.


We searched two Chinese databases (CEPS, and the Chinese Journal database) and four English databases (CINAHL, Medline, PubMed, and the Cochrane Central Register of Controlled Trials) to identify studies comparing the effects of bowel preparation with NaP and PEG. Evaluations of study quality were conducted by the 2011 Oxford Centre for Evidence Based Medicine Levels of Evidence and the Cochrane Collaboration’s tool for assessing risk of bias. Meta-analyses were performed by the random effect model. Pooled effects of efficiency in bowel preparation and adverse events of NaP and PEG were calculated.


Seventeen studies were included in the meta-analyses. Fourteen studies provided comparisons between NaP and 4-L PEP and the homogeneity was reached after 2 studies were excluded. The efficiency of NaP is significantly better than using the PEG (OR=1.55, 95% CI=1.15-2.09, p=.004). Nap and PEG did not differ in nausea, but NaP presented less vomiting responses than PEG.


Meta-analyses of efficacy in bowel preparation and related adverse events supported NaP as an effective strategy. Application of NaP in bowel cleaning will also provide patient comfort during the procedure.