title: Adequacy of flexible sigmoidoscopy with biopsy for diarrhea in patients under age 50 without features of proximal disease.
abstract: BACKGROUND
  The optimal endoscopic investigation of diarrhea in patients under age 50 without specific features of right-sided colonic/ileal disease is inadequately defined.
  
  
  OBJECTIVE
  To assess the potential additional yield of colonoscopy over flexible sigmoidoscopy (FS) in this group.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  Two teaching hospital endoscopy units.
  
  
  METHODS
  This study involved all patients under age 50 who had a colonoscopy between 1997 and 2007 to investigate diarrhea, without high-risk features of right-sided colonic/ileal disease, inflammatory bowel disease (IBD), or rectal bleeding.
  
  
  METHODS
  Colonoscopy and biopsy.
  
  
  METHODS
  Diagnostic yield of colonoscopy over FS with biopsy.
  
  
  RESULTS
  Colonoscopic appearances were abnormal in 126 of 625 eligible patients (20%); 72% of abnormalities were within reach of FS. The most common endoscopic abnormality was suspected inflammation in 60 patients (10% overall), reportedly confined to the proximal colon or ileum in 22 patients (37% of this group). Histology from areas of suspected inflammation revealed features of IBD in 68% of patients, but results were normal in the remainder. In the 22 patients with suspected isolated proximal disease, 8 patients (36%) had normal histology results, and a further 6 had left-side colon biopsies demonstrating IBD. In patients with macroscopically normal colons, histological evidence of IBD or microscopic colitis occurred in 14 and 12 patients, respectively, with changes in the left side of the colon in 93% of patients. In this patient group, 85% of IBD or microscopic colitis could have been detected by FS and biopsy. The negative predictive value of FS with biopsy was 98% for IBD and 99% for microscopic colitis.
  
  
  CONCLUSIONS
  Retrospective study.
  
  
  CONCLUSIONS
  FS is adequate for the investigation of diarrhea in patients under age 50 who lack other features, but its yield depends on biopsy of the left side of the colon.
authors.affiliation: Department of Gastroenterology, Hammersmith Hospital, Imperial College Healthcare NHS Trust, London, UK. matthew.shale@path.ox.ac.uk
authors.forename: Matthew J H
authors.initials: MJ
authors.lastname: Shale
authors.forename: Julian R F
authors.initials: JR
authors.lastname: Walters
authors.forename: David
authors.initials: D
authors.lastname: Westaby
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001706:Biopsy / Q000379:methods*; D003937:Diagnosis, Differential; D003967:Diarrhea / Q000453:epidemiology / Q000209:etiology / Q000473:pathology*; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007077:Ileal Diseases / Q000150:complications / Q000453:epidemiology / Q000473:pathology*; D015994:Incidence; D008297:Male; D008875:Middle Aged; D018583:Pliability; D012189:Retrospective Studies; D012810:Sigmoid Diseases / Q000150:complications / Q000453:epidemiology / Q000473:pathology*; D020694:Sigmoidoscopes; D012812:Sigmoidoscopy / Q000379:methods*; D006113:United Kingdom / Q000453:epidemiology; D055815:Young Adult