Introduction Bile acid malabsorption (BAM) is a common cause of diarrhoea in Crohn’s disease (CD) patients with ileal resection and can lead to complications such as renal and biliary stone disease. BAM is usually diagnosed by selenium labelled homo-taurocholic acid test (⁷⁵ SeHCAT) but its availability is limited. Thus, large proportions of resected CD patients either remain undiagnosed or subject to empirical therapy. There is a paucity of studies examining the correlation between length of ileal resection and severity of BAM which will be of particular use to clinicians with no recourse to diagnostic testing for BAM.

Methods We identified all CD patients with a prior surgical resection who underwent ⁷⁵ SeHCAT testing at our institute. Testing was based on the treating clinician’s discretion. The length of resected ileum was recorded from histopathology report. Correlation between length of resected ileum and percentage retention on ⁷⁵ SeHCAT was assessed using a Spearman’s correlation test. Response to treatment with bile salt sequestrant and ⁷⁵ SeHCAT retention values (using a cut point of 5%) was analysed using Fisher’s exact test.

Results A total of 40 patients were identified with a mean age of 45 (SD±13), of which 6 (15%) were men. The median length of resected ileum was 22.8 cms (range 5.8–61.0 cms) with a median of 1 resection (range 1–4). Overall, 38 patients (95%) had ⁷⁵ SeHCAT retention values of <10% and 36 (90%) had retention of <5%. There was no correlation between ⁷⁵ SeHCAT retention and length of ileal resection (Spearman’s rho: -0.19, P = 0.24). Data on response to treatment was available for 30 patients, of who 21 (70%) responded and 9 (30%) failed to respond to bile salt sequestrant therapy. Three of the responders (14%) had ⁷⁵ SeHCAT values of >5% and the remaining 18 (86%) had values <5%. All of the non-responders had ⁷⁵ SeHCAT retention values <5% (Fisher’s exact, two tailed P = 0.53).

Conclusion There was no correlation between length of ileal resection and severity of BAM as defined by ⁷⁵ SeHCAT retention values. Response to bile salt sequestrant therapy was not dependent on ⁷⁵ SeHCAT retention values though overall clinical response was good.

Disclosure of Interest K. Lo: None Declared, H. Riyat: None Declared, Y. Prasad: None Declared, S. Subramanian Speaker bureau with: MSD, Abbvie, Shire, Ferring, Actavis, Conflict with: Advisory board Boehringer-Ingelheim, Vifor pharma, MSD, Abbvie, Shire