Although recognised as a cause of chronic diarrhoea for over forty years, diagnostic tests and treatments for bile acid malabsorption (BAM) remain controversial. Recent National Institute for Health and Care Excellence (NICE) guidelines highlighted the lack of evidence in the fi eld, and called for further research. This retrospective study explores the BAM subtype and severity, the use and response to bile acid sequestrants (BAS) and the prevalence of abnormal colonic histology. 264 selenium-75-labelled homocholic acid conjugated taurine (SeHCAT)-tested patient records were reviewed and the severity and subtype of BAM, presence of colonic histopathology and response to BAS were recorded. 53% of patients tested had BAM, with type-2 BAM in 45% of patients with presumed irritable bowel syndrome. Colonic histological abnormalities were similar overall between patients with (29%) or without (23%) BAM (p=0.46) and between BAM subtypes, with no signifi cant presence of infl ammatory changes. 63% of patients with BAM had a successful BAS response which showed a trend to decreased response with reduced severity. Colestyramine was unsuccessful in 44% (38/87) and 45% of these (17/38) were related to medication intolerance, despite a positive SeHCAT. 47% (7/15) of colestyramine failures had a successful colesevelam response. No patient reported colesevelam intolerance. Quantifying severity of BAM appears to be useful in predicting BAS response. Colesevelam was better tolerated than colestyramine and showed some effi cacy in colestyramine failures. Colestyramine failure should not be used to exclude BAM. Colonic histology is of no relevance.

The affiliation for Professor John McLaughlin was incorrect. The correct affiliation is printed above.

positive biopsy cases. A proportion of patients will not have serological tests going straight to endoscopy as first line investigation for their anaemia. Serological testing remains useful in primary care and for physicians to diagnose coeliac disease; however it is important to be aware of the small number of cases (approximately 5%) that will be missed when relying on serology alone.

IntroductionSmall intestinal bacterial overgrowth (SIBO) testing is confounded by transit time, which can be increased in a number of surgical conditions. This study aims to evaluate whether patients who have undergone a gastric bypass, small bowel resection or who have been diagnosed with short bowel syndrome have a higher prevalence of SIBO than patients who have not, and whether they respond to antibiotic treatmentMethodsIn total, 520 adult patients (360 female, 160 male, mean age 49) who underwent hydrogen and glycocholate-methane breath tests for a suspicion of SIBO between the dates 01/01/2010 and 31/12/2013 were evaluated. Their clinical information including their test results, working diagnosis, management and outcomes of management were recorded.Results84 patients had undergone a gastric bypass (31), small bowel resection (27) or had been diagnosed with short bowel syndrome (26). 40 of these patients tested positive in both hydrogen and glycocholate-methane breath tests (48.2%). 437 patients with normal anatomy were also tested over the same period, of which 61 tested positive (14.0%). (48.2% vs 14.0%, Chi-square statistic = 50.8911, p = 0). 34 patients who had undergone a gastric bypass, small bowel resection or had been diagnosed with short bowel syndrome who tested positive were treated with antibiotics. 28 (82.4%) benefitted from this. 56 patients who tested positive in the other group were given antibiotics, 41 (73.2%) of whom benefitted from this.ConclusionPatients who had undergone a gastric bypass, small bowel resection or have been diagnosed with short bowel syndrome have a much higher rate of positive SIBO test results compared to patients who have not, and have a similar response rate to antibiotic therapy. This suggests these post-surgical patients have a higher incidence of true SIBO than those with normal anatomy and benefit from antibiotics. This implies these are true positive cases and not false positives due to shortened transit times. Future studies controlling for transit would help clarify these findings further.Disclosure of InterestNone Declared

IntroductionChoice of antibiotic treatment in patients who test positively for Small Intestinal Bacterial Overgrowth (SIBO) can be difficult. No controlled trial has examined the clinical efficacy of antibiotics in SIBO. This study aimed to identify which antibiotics are the most effective in treating SIBO in a real world retrospective cohort.Methods520 adult patients (360 female, 160 male, mean age 49) who underwent hydrogen and glycocholate-methane breath tests for a suspicion of SIBO between the dates 01/01/2010 and 31/12/2013 were evaluated. The clinical information of patients who tested positively in both tests was recorded. Information was also gathered as to the antibiotic they were prescribed and whether they received symptomatic benefit from their treatment.ResultsA total of 90 patients who tested positive were prescribed antibiotics (59 female, 31 male, mean age 56). 69 (76.7%) of these patients benefitted from their management. 32 patients who tested positive were given cyclical antibiotics. The efficacy of cyclical antibiotics compared with the combined efficacy rates of other antibiotic regimes in treating patients with a positive breath test result was 93.8%. (93.8% vs 67.2%, Chi-square = 8.1, p = 0.004). 15 patients who tested positive were given rifaximin. The efficacy of rifaximin in treating patients with a positive breath test result compared with the combined efficacy of other antibiotic regimes was 80%. (80% vs 76% Chi-square = 0.112, p = 0.738). 18 patients who tested positive were given metronidazole. The efficacy of metronidazole in treating patients who tested positive in the breath tests compared with combined efficacy rates of other antibiotics was much lower at 50% (50% vs 83%, Chi-square = 8.9441, p = 0.0028).ConclusionMetronidazole appeared inferior to rifaximin monotherapy for treating SIBO. Cyclical antibiotics appeared most effective. These findings should be explored further in randomised controlled prospective trials to determine the optimal treatment regime.Disclosure of InterestNone Declared