Comparing bowel preparation for colonoscopy — do you need a gallon?

“The procedure was nothing at all . . . it was the prep that was awful.” A common response to colonoscopy which we hear many times.

Recent randomized research showed low volume sodium phosphate solution cleaned the bowel as effectively and was much higher in patient acceptance than the large volume PEG solutions.

In an effort to compare both effective bowel cleansing and patient acceptance, researchers randomized colonoscopy patients to prepare for the test with sodium phosphate solutions, polyethylene glycol,or senna solutions. Sodium phosphate solution is marketed in the US as Fleet’s PhosphoSoda. Polyethylene glycol or PEG is available as Colyte, Golytely, and Nulytely. Senna is an herbal preparation that is dissolved in clear liquid. Both sodium phosphate and senna require much less volume of liquid be drunk than PEG.

Body weight, blood pressure, and blood chemistry were measured before and after the bowel preparations. Patients completed a questionnaire after the colonoscopy listing side effects and rating their satisfaction with the method of bowel prep. Gastroenterologists rated each preparation as clean, suboptimal or dirty.

170 patients were randomized to 3 groups. Group 1 prepared with sodium phosphate solution, Group 2 with PEG, Group 3 with a senna solution.

There were no significant differences in body weight changes or laboratory tests among the three groups. Side effects during the prep were not sigificantly different except for more cramping in the senna group.

Overall cleansing was the same for the groups. However the senna-prepared group had the highest level of fecal contamination (17.8%).

When asked if they would like the same method of preparation again, more patients in the sodium phosphate group said yes (59%). The fewest senna-prepared patients agreed (6.8%).

A team of gastroenterologists from Turkey reported their results in the October, 2005 issue of *Digestive Endoscopy* (Volume 17 Issue 4 Page 290). They concluded:

When compared with respect to their efficacies in colon cleansing, safety of application, ease of usage, and side-effects, no significant differences were noted between sodium phosphate, polyethylene glycol and senna solutions. Nevertheless, due to its greater tolerability, requirement of a shorter period of time in colon cleansing, and lower cost, we recommend the use of sodium phosphate in bowel preparation prior to colonoscopy.

[Read an abstract of the study in *Digestive Endoscopy.*](http://www.blackwell-synergy.com/doi/abs/10.1111/j.1443-1661.2005.00547.x)

[Read a similar study done in India in 2002, not including senna](http://www.indianjgastro.com/article.asp?issn=0254-8860;year=2002;volume=21;issue=6;spage=219;epage=21;aulast=Reddy;type=0)