Is bowel preparation useful before radiography of the renal tract in patients with spinal cord injury

Objectives To assess, in a blinded study, the usefulness of bowel preparation in improving the quality of radiography of the renal tract in patients with spinal cord injury (SCI). Patients and methods Plain abdominal radiographs of 56 patients with SCI were selected; 24 of the patients had received bowel preparation and 32 had not. The films were independently assessed by one radiologist and one urologist unaware of the treatment and identity of the patients. Each film was divided into five regions of interest and scores of 1–4 (1 for least and 4 for best visibility) assigned to each area. In films with a low aggregate visibility score ( 12), the cause of poor visibility was assessed in relation to faecal residue and gas. Results The difference between the overall mean visibility score for bowel-prepared and unprepared patients was not statistically significant. In films with poor visibility, gas shadows predominated over bowel shadows in the bowel-prepared group, although this trend was not statistically significant. Of the five areas, the bladder was scored as being the most clearly seen in both groups. Conclusions These findings suggest that bowel preparation does not increase the diagnostic value of radiographs of the renal tract in patients with SCI.