title: Comparison of relative risks of urinary stone formation after surgery for ulcerative colitis: conventional ileostomy vs. J-pouch. A comparative study.
abstract: OBJECTIVE
  Urinary stone formation is a widely recognized complication o f inflammatory bowel disease and the surgical management of these conditions. Previously the fecal volume and chemistry after restorative proctocolectomy with J-pouch were found to be similar to conventional panproctocolectomy with permanent ileostomy. The purpose of this study was to investigate whether the relative risks of urinary stone formation were less following J-pouch than following conventional ileostomy.
  
  
  METHODS
  The risk of urinary stone formation was determined from the chemical composition of two consecutive 24-hour urine samples in 13 patients with well-functioning ileostomies, 15 patients with well-functioning J-pouches, and 17 control volunteers.
  
  
  RESULTS
  Compared with controls, ileostomy and J-pouch patients had significantly lowered urinary volumes and pH, higher concentrations of calcium and oxalate, and an increased risk of forming uric acid stones. In addition there was an increased risk of forming calcium stones in the conventional ileostomy group. This risk was found not to be present in the J-pouch group.
  
  
  CONCLUSIONS
  The risks of forming uric acid stones are high for both ileostomy and J-pouch patients, but our results suggest that there will be a reduction in calcium stone formation after J-pouch.
authors.affiliation: University Department of Surgery, Auckland Hospital, New Zealand.
authors.forename: P M
authors.initials: PM
authors.lastname: Christie
authors.forename: G S
authors.initials: GS
authors.lastname: Knight
authors.forename: G L
authors.initials: GL
authors.lastname: Hill
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D003093:Colitis, Ulcerative / Q000601:surgery*; D005260:Female; D006801:Humans; D007081:Ileostomy / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D016737:Proctocolectomy, Restorative / Q000009:adverse effects*; D012306:Risk; D012307:Risk Factors; D014545:Urinary Calculi / Q000209:etiology* / Q000652:urine