title: The clinical characteristic and risk of capsule incomplete and retention in Crohn's disease.
abstract: OBJECTIVE
  To evaluate capsule endoscopy in terms of incomplete examinations and capsule retentions, to describe the characteristic of these events and to find risk factors for these events.
  
  
  METHODS
  This retrospective and consecutive case-control study includes data of 204 capsule enteroscopy examinations in patients with Crohn's Disease, performed at the first hospital affiliated to zhejiang university medical school from June 2003 to April 2014.
  
  
  RESULTS
  The frequency of complete examinations was 56.9%. Male gender (OR=2.48, P=0.026), abdominal pain (OR=2.88, P=0.002), melena/bloody stools/OB+ (OR=3.34, P=0.009) were risk factors for an incomplete examination. Capsule retention occurred in 8.33% (n=17). The ratio of male and female was 12:5. While the average age of these patients was 42.2±16.2, and the average course of disease was 52.5±46.6 months. Of the seventeen cases of retained capsules, four patients chose to undergo surgery to remove the capsule for occurring symptoms of intestinal obstruction, spontaneous passage occurred in twelve patients after medical treatment, and one patient still have the capsule retained after 16 months of expectation. The longest capsule retained time in patients was four years. Risk factors for capsule retention was abdominal distention (OR=8.45, P=0.006).
  
  
  CONCLUSIONS
  The majority of capsule endoscopy retention develops into spontaneous passage after medical treatment. Therefore capsule endoscopy is considered a safe procedure, although obstructive symptoms and serious complications due to capsule retention can be found in patients with known Crohn's disease.
authors.affiliation: Department of Gastroenterology, First Affiliated Hospital, Medical College of Zhejiang University Hangzhou 310003, Zhejiang Province, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Du
authors.affiliation: Department of Gastroenterology, First Affiliated Hospital, Medical College of Zhejiang University Hangzhou 310003, Zhejiang Province, China.
authors.forename: Danmei
authors.initials: D
authors.lastname: Pan
authors.affiliation: Department of Gastroenterology, First Affiliated Hospital, Medical College of Zhejiang University Hangzhou 310003, Zhejiang Province, China.
authors.forename: Panpan
authors.initials: P
authors.lastname: Ma
authors.affiliation: Department of Gastroenterology, First Affiliated Hospital, Medical College of Zhejiang University Hangzhou 310003, Zhejiang Province, China.
authors.forename: Bingling
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Department of Gastroenterology, First Affiliated Hospital, Medical College of Zhejiang University Hangzhou 310003, Zhejiang Province, China.
authors.forename: Chunxiao
authors.initials: C
authors.lastname: Chen
keywords: Crohn’s disease; capsule endoscopy; retention; risk factors