title: Incidence and predictive factors for positive75SeHCAT test: improving the diagnosis of bile acid diarrhoea.
abstract: OBJECTIVE
  To determine the value of75SeHCAT retention in determining bile acid diarrhoea (BAD), treatment response and predictors of a positive result.
  
  
  METHODS
  Retrospective casenote review of consecutive patients undergoing75SeHCAT from 2008 to 2014, including gender, age, history, clinical, and laboratory parameters. This included diseases associated with Type 1 BAD (ileal resection, Crohn's disease) and Type 3 BAD. Chi-squared test and logistic regression determined factors predictive of BAD. Subjective response to treatment with bile acid sequestrants (BAS) was analysed with respect to the75SeHCAT result.
  
  
  RESULTS
  Of 387 patients, 154 (39.7%) were male and average age was 50 years. Ninety-five patients (24.5%) were investigated for Type 1 BAD, 86 (22.2%) for Type 3, and 206 patients (53.2%) for Type 2 or idiopathic BAD. There was a large increase in the number performed with time but no difference in percentage positive tests. One hundred and seventy-nine patients (46.2%) had BAD. Positive result was commonest in possible Type 1 and they had most severe BAD. Ninety-nine patients had severe BAD (<5%75SeHCAT retention), 47 moderate BAD (5% to <10% retention), and 33 mild BAD (10% to <15% retention). Predictors of a positive75SeHCAT were right hemicolectomy (OR 4.88), cholecystectomy (OR 2.44), and Crohn's (OR 1.86). A positive75SeHCAT predicted a good or partial response to BAS of 66.7% (mild), 78.6% (moderate), or 75.9% (severe BAD).
  
  
  CONCLUSIONS
  75SeHCAT test use increased in 2008-2014, with high positive results throughout. Ileal resection, Crohn's, and cholecystectomy independently predict BAD.75SeHCAT predicted response to BAS.
authors.affiliation: a Department of Gastroenterology , Royal Cornwall Hospital , Truro , Cornwall , UK.
authors.forename: Iain Alexander
authors.initials: IA
authors.lastname: Murray
authors.affiliation: a Department of Gastroenterology , Royal Cornwall Hospital , Truro , Cornwall , UK.
authors.forename: Linzi Karen
authors.initials: LK
authors.lastname: Murray
authors.affiliation: a Department of Gastroenterology , Royal Cornwall Hospital , Truro , Cornwall , UK.
authors.forename: Kathy Louise
authors.initials: KL
authors.lastname: Woolson
authors.affiliation: a Department of Gastroenterology , Royal Cornwall Hospital , Truro , Cornwall , UK.
authors.forename: Hisham
authors.initials: H
authors.lastname: Sherfi
authors.affiliation: b Department of Nuclear Medicine , Royal Cornwall Hospital , Truro , Cornwall , UK.
authors.forename: Ivor
authors.initials: I
authors.lastname: Dixon
authors.affiliation: c Department of Research and Development , Royal Cornwall Hospital , Truro , Cornwall , UK.
authors.forename: Joanne
authors.initials: J
authors.lastname: Palmer
authors.affiliation: b Department of Nuclear Medicine , Royal Cornwall Hospital , Truro , Cornwall , UK.
authors.forename: Tom
authors.initials: T
authors.lastname: Sulkin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001647:Bile Acids and Salts / Q000378:metabolism*; D002763:Cholecystectomy; D003424:Crohn Disease / Q000175:diagnosis* / Q000503:physiopathology*; D003967:Diarrhea / Q000175:diagnosis* / Q000188:drug therapy* / Q000209:etiology; D005260:Female; D006801:Humans; D016015:Logistic Models; D008286:Malabsorption Syndromes / Q000175:diagnosis* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012644:Selenium Radioisotopes; D013656:Taurocholic Acid / Q000031:analogs & derivatives; D006113:United Kingdom; D055815:Young Adult
chemical_list: D001647:Bile Acids and Salts; D012644:Selenium Radioisotopes; D013656:Taurocholic Acid; C033638:23-seleno-25-homotaurocholic acid
keywords: 75SeHCAT; Bile acid diarrhoea; bile acids and salts; chronic diarrhoea; colestyramine; malabsorption syndromes; sequestrants