AGA Abstracts Table 1 Mo1636 Prevalence and Risk-Factors of Post Infectious Irritable Bowel Syndrome: A Systematic Review and Meta-Analysis Fabiane B. Klem, Akhilesh Wadhwa, Larry Prokop, Wendy Sundt, Gianrico Farrugia, Michael Camilleri, Siddharth Singh, Madhusudan Grover Introduction: Infectious enteritis (IE) is one of the most commonly identified risk factors for development of IBS. A number of studies have looked at the prevalence and host and enteritis related factors associated with the development of post infectious IBS (PI-IBS). However, these have looked at different pathogens, in different settings using variable methodologies. Aim: Our aim was to systematically review and analyze the literature reports to determine prevalence, risk factors, and pathogen-specific risk of PI-IBS. Methods: We updated an existing systematic review conducted in 2007, with a comprehensive literature review of multiple electronic databases through August 2015. We included cohort studies with documented IE (defined by positive culture or clinical suspicion) reporting prevalence of IBS (defined by Rome I, II or III criteria) at different time points after exposure. Data extraction for prevalence, risk factors (host and pathogen related) was performed in duplicate using a standardized form. Random-effects meta-analysis was used to estimate PI-IBS preva- lence at 6m, 12m and >12m. When a comparator group without IE was reported, we estimated relative risk (RR) of developing PI-IBS. To identify risk factors associated with PI- IBS, we performed meta-analysis combining maximally adjusted odds ratios (OR) for each factor in the included studies, to estimate a summary OR with 95% confidence interval (CI) for each risk factor. Results: 29 studies were included (n=16,446 IE patients) with follow up ranging from 3m to 10 yrs. The pooled prevalence of PI-IBS within 12m after IE was 10.1% (95% CI=4.1-22.6%, I 2 : 97%); the corresponding prevalence beyond 12m was 17.8% (95% CI=8.6-33.1%, I 2 : 97%). As compared to individuals without IE, individuals with IE had 2.9 times higher risk of developing PI-IBS within 12m (95% CI=2.4-3.6, I 2 :15%) and 2.2 times higher risk beyond 12m (95% CI=1.7-2.9, I 2 :78%). Overall, patients with protozoal enteritis had the highest prevalence of PI-IBS (41.9%, 95% CI=28.7-56.6), followed by bacterial enteritis (14.2%, 95% CI=8.0-24.1); however, within 12m after IE, patients exposed to viral enteritis had highest prevalence of PI-IBS. Antibiotic exposure (OR, 1.6; 95% CI= 1.1-2.2), prevalent anxiety (OR, 1.4; 95% CI=1.1-1.7) and depression (OR, 1.3; 95% CI= 1.0-1.6) at time of IE were associated with higher risk of PI-IBS; smoking was not associated with an increased risk of PI-IBS (OR, 1.1; 95% CI=0.9-1.5). Conclusion: IE is associated with a 10-18% prevalence of PI-IBS and a RR of 2.2-2.9 as compared to the unexposed. Overall, protozoal enteritis is associated with the greatest risk of PI-IBS and viruses may be most likely to cause short term PI-IBS. Antibiotic use during IE and psychological distress at the time of IE are potentially modifiable risk factors associated with the development of PI-IBS. Mo1637 Age but Not Sex Affects the Sensitivity of the Rome IV Diagnostic Criteria for IBS William E. Whitehead, Olafur S. Palsson, Miranda A. van Tilburg, Magnus Simren Background: The irritable bowel syndrome (IBS) is believed to be more prevalent in women than men and to decline with age. Aims: (1) Confirm the effects of sex and age on IBS prevalence, (2) determine whether the sensitivity and specificity of the Rome IV Diagnostic Questionnaire (R4DQ) varies with sex or age, and (3) assess whether this could explain sex and age effects on prevalence. Methods: Nine academic gastroenterology (GI) clinics in the US, Canada, and UK referred patients with a previous clinical diagnosis of IBS or other functional GI disorders to a website to complete the R4DQ. Colonoscopy was required before diagnosing IBS. Sensitivity was defined as the proportion of 375 patients with a primary clinical diagnosis of IBS who fulfilled Rome IV criteria on the R4DQ. A separate population-based sample of 2000 from each country (US, UK, Canada) was recruited by Qualtrics (Provo, Utah). This sample was stratified by country, sex (half males), and age (40% aged 18-39, 40% aged 40-64, and 20% aged 65+). Specificity was defined as the proportion of subjects who did not fulfill IBS criteria after excluding anyone with a lower GI clinical diagnosis. Results: The clinical validation sample included 843 tertiary care GI patients, and the population survey included 5,931 people. The prevalence of IBS in the population sample was greater in women than men (7.4% vs. 4.1%, p<.001) and declined by age 65 (Figure 1). Overall sensitivity of the Rome IV Diagnostic Questionnaire was 62.7% and specificity was 97.0%. The sensitivity of the R4DQ was not significantly greater in women vs. men, but was significantly lower in subjects aged 65+ compared to younger subjects (Figure 2). Specificity of the diagnostic questionnaire was greater than 96% in all gender and age subgroups. Conclusions: Sex does not significantly affect the sensitivity of the R4DQ and cannot explain the 80.6% greater prevalence of IBS in women compared to men. However, the sensitivity of the R4DQ does decline with age and may contribute to the reduced prevalence of IBS in older adults. The modest sensitivity and excellent specificity of the Rome IV Diagnostic Questionnaire is adequate for research, epidemiology, and clinical management. [Supported by the Rome Foundation.] S-738 AGA Abstracts Figure 1 Figure 2 Mo1638 Intolerance and Hypersensitivity During and After an Inulin (Fructan) Breath Test. A Study in Irritable Bowel Syndrome and Healthy Controls Xaira J. Rivera Gutierrez, Shareni Galvez-Rios, Mercedes Amieva-Balmori, Olivia Rascon Sosa, Hector Alonso Taboada Liceaga, Paulo Cesar Gomez-Castaños, Job Reyes-Huerta, Yolopsi de Jesús Sanchez-Maza, Jose M. Remes Troche Background: Fructans are oligo- or polysaccharides that include short chains of fructose units with a terminal glucose molecule. Inulin, one of the most common fructans present in a Western diet (e.g. wheat, onion, garlic,etc), has been used as an alternative substrate for H(2)-based breath testing of the orocecal transit time. Recently, Rao et al (DDW 2014) in found that 55% of IBS patientes had fructan malabsorption based on a positive fructan breath test (FBT). Aim: (1) To evaluate the prevalence of fructan intolerance and fructan hypersensitivity during a FBT and (2) Symptoms persistence 24 hrs after the FBT in IBS patients as well in healthy controls. Methods: Twenty one IBS (Rome III) patients (13 female, mean age 46 ± 15 years) and 20 asymptomatic healthy controls (10 female, 47.4 ± 15 years) were evaluated. After an overnight fast, subjects ingested 10 g of fructan dissolved in 100 cc water. H2 were collected at baseline and every 15 minutes for 3 hours (Gastrolyzer, Bedfont, UK) A change 20 ppm over baseline H2. Symptoms (abdominal pain, cramping, bloating, fullness, nausea, belching, indigestion, diarrhea, gas, distention) were assessed at baseline, during the BT and 24 hours after using a likert scale . Patients were classified in (1) Intolerance, defined as gastrointestinal symptoms and malabsorption (augmentation in the level of H2), (2) Hypersensitivity, when there was no significant increase in H2 but the patients report symptoms during the study, and (3) Normals, subjects without neither malabsorption or symptoms. Results: Among IBS subjects, 4 (19%) had IBS-C, 6 IBS-D (28.65) and 11 (52-4%) IBS-M. Positive FBTs were found in 4 IBS subjects (19%) and 1 control (5%, p=0.18). However, 85.7% (n=18) of IBS patients had symptoms during the FBT compared to 50% of controls (p=0.02). Bloating (p=0.04) and abdominal pain (p= 0.018) were more common in IBS patients during the test compared to controls. Prevalence of malabsorption and hypersensitivity was more common in IBS patients than controls (Figure). Hypersensitive patients reported more belching (p=0.011) and dyspeptic symptoms during the FBT (p=0.001). Patients with hypersensitivity to fructans reported more nauseas 24 hrs after the FBT (17.5% vs. 5%, p=0.03) but patients with malabsorption reported more frequently diarrhea (40% vs 4.3%, p=0.04). Although both groups had a significant increase in the abdominal girth after the FBT, the increase was significantly higher in IBS patients than controls (basal 90.9 cm vs. post FBT 93.9 cms, p=0.001). Conclusions: Although up to 50% of asymptomatic subjects develop symptoms after a fructan challenge, IBS patients has a higher prevalence (85%) of hypersensitivity to inulin. A higher increase in abdominal waist and persistence of symptoms after 24 hrs. suggest that fermentation of this carbohydrate is abnormal in IBS patients.