Epidemiology of irritable bowel syndrome in hospitalized patients with inflammatory bowel disease: Nationwide Inpatient Sample analysis from 2007-2016

BACKGROUND: Despite effective treatments for inflammatory bowel disease (IBD), patients in remission may still suffer from gastrointestinal symptoms attributable to overlying irritable bowel syndrome (IBS). In this population-based cohort study, we investigated the epidemiology of IBS in hospitalized IBD patients and explored the differences between hospitalized IBD-IBS vs. IBD patients to distinguish this patient population. METHODS: Using the Nationwide Inpatient Sample database from 2007-2016, we identified patients with a primary or secondary discharge diagnosis of IBD, with or without IBS, using ICD-9 and ICD-10 codes. We extracted information on demographics, psychological comorbidities, IBD complications, cost and duration of stay of each group, from either discharge records or diagnosis codes. These were analyzed using SAS version 4.0. RESULTS: There was a rise in the prevalence of IBS among inpatients with ulcerative colitis (P=0.025) and Crohn’s disease (P=0.0014) over the study period. This study revealed that IBD patients with IBS tend to be female, younger, are less likely to be morbidly obese and have higher rates of psychological disorders (P<0.001) compared to IBD patients with no IBS co-diagnosis. They also have fewer IBD-specific complications, such as strictures, obstruction, fistula and abdominal abscess (P<0.001). Shorter hospital stays (P<0.001) and lower hospital charges (P<0.001) were also noted in these patients. CONCLUSIONS: IBD patients with IBS are significantly different from other IBD patients, and are associated with less severe disease, a shorter hospital stay and lower hospital expenses. Early and accurate classification of this patient population may prevent unnecessary treatment and hospitalization in the future.