Prevalence of irritable bowel syndrome-type symptoms in patients with inflammatory bowel disease in remission: a systematic review and meta-analysis

Background Patients with inflammatory bowel disease (IBD) often report symptoms compatible with irritable bowel syndrome (IBS), which might have an effect on psychological health. However, previous estimates of the magnitude of this issue have not accounted for ongoing inflammation as the potential cause. We updated a previous systematic review and meta-analysis to determine prevalence of IBS-type symptoms in patients with IBD in remission to better quantify the magnitude of this issue. Methods In this systematic review and meta-analysis, Embase, Embase Classic, and MEDLINE were searched (from Jan 1, 2012, to May 11, 2020) to identify prospective case-control or cross-sectional studies reporting prevalence of symptoms meeting diagnostic criteria for IBS in adults with IBD in remission. Studies were required to have recruited an unselected adult population (more than 90% of participants aged >= 16 years) with histologically or radiologically confirmed IBD and include at least 50 participants. Pooled prevalence and odds ratios (ORs) with 95% CIs were calculated according to the definition of remission, criteria used to define IBS-type symptoms, and type of IBD. The association between IBS-type symptom reporting and psychological comorbidity was examined using weighted mean difference (WMD) or standardised mean difference (SMD) in anxiety and depression scores between those reporting IBS-type symptoms and those not, for cases in which these data were available. Findings Of 3370 studies identified, 27 were eligible, of which 18 were newly identified. Among 3169 patients with IBD in remission, pooled prevalence of IBS-type symptoms was 32.5% (95% CI 27.4-37.9; I-2=90.1%). Prevalence was lower when remission was defined by endoscopic assessment (23.5%, 95% CI 17.9-29.6; I-2=59.9%) or histological assessment (25.8%, 95% CI 20.2-31.7; I-2=not applicable) than when defined by validated clinical disease activity index (33.6%, 26.3-41.2; I-2=91.8%) and higher in Crohn's disease than in ulcerative colitis (36.6%, 29.5-44.0; I-2=82.9% vs 28.7%, 22.9-34.8; I-2=87.2%). Anxiety (WMD 2.5; 95% CI 0.8-4.3) and depression (SMD 0.64; 0.44-0.84) scores were significantly higher among those who reported IBS-type symptoms than in those who did not. Interpretation Prevalence of symptoms compatible with IBS in patients with IBD varied according to how remission was defined. However, even when stringent criteria such as endoscopic or histological remission were used, about a quarter of patients reported these symptoms. Such symptoms were more common in patients with Crohn's disease and were associated with psychological comorbidity. Addressing psychological wellbeing might improve outcomes in this specific group of patients.