Functional symptoms in inflammatory bowel disease and their potential influence in misclassification of clinical status

SummaryBackground : Functional symptoms occur in inflammatory bowel disease probably more than in the general population. Existing disease indices rely heavily on symptoms that may be organic or functional. This may explain inconsistencies between recent therapeutic trials in inflammatory bowel disease. Clinically, misinterpretation can lead to over‐treatment of functional symptoms with potent agents, and to under‐treatment of inflammatory bowel disease when inflammatory features are more subtle.Aim : To assess functional symptoms in inflammatory bowel disease and to devise simple means of their evaluation.Methods : Patients with Crohn's disease, ulcerative colitis, and irritable bowel syndrome completed questionnaires, generating inflammatory bowel disease and irritable bowel syndrome indices. Data from outliers selected as exemplars were employed to create a new index.Results : One hundred and ninety patients completed questionnaires. Overall, Crohn's and irritable bowel syndrome patients had similar functional features. The new scoring system was based on the eight apparently discriminant symptoms. Prospective evaluation in a separate cohort of 180 inflammatory bowel disease patients yielded scores that are independent of established indices, inflammatory markers and psychometric scores.Conclusions : Patients with Crohn's report comparable rates of apparently functional symptoms to those with irritable bowel syndrome. A new score has been developed to help in their identification. This has the potential to guide therapeutic decisions and optimize future trial recruitment.