Is Bowel Preparation Before Excretory Urography Necessary? A Prospective, Randomized, Controlled Trial

Abstract

A prospective, randomized, single blind, controlled trial was performed to determine whether routine bowel preparations are necessary for satisfactory visualization of the urinary system during IVP and compare the side effects of several bowel preparation methods. A total of 200 patients between 17 and 70 years old at the outpatient department who were prescribed IVP were enrolled in this prospective study. Patients were divided into 4 groups and randomly received liquid supper, senna, magnesium sulfate solution and PEG-ELS as bowel preparation before IVP. Control and contrast images were assessed by a radiologist and a urologist blinded to the bowel preparation. IVP was given a visualization score, a fecal residue score, a bowel gas score and an overall quality score. Images were also divided into anatomical sections to assess visualization, and the effect of fecal residue and bowel gas. Questionnaires were prepared about the side effects of bowel preparation. For contrast images there was no significant difference in terms of visualization,, fecal residue, bowel gas and overall quality scores among the 4 groups. The same result was seen on the control image except for fecal residue scores, when the senna and PEG-ELS groups had a lower fecal residue score than the liquid supper group (p = 0.001). Interestingly when considering sectional images, the right renal region of the control image showed that the senna and PEG-ELS groups had better visualization scores with less bowel gas and fecal residue than the liquid supper only group. Patients in all 3 laxative bowel preparation groups except the liquid supper group reported side effects. There was no statistically significant difference among these 3 groups in the attitude toward ingesting laxatives again. Our results suggest that routine bowel preparation prior to IVP does not improve the visibility or overall quality of control or contrast images, while patients experience certain side effects due to the bowel preparation. The laxative bowel preparation may be helpful only when visualizing the right renal region on the control image.