Treatment of Functional Bowel Disorders

Overview

The primary purpose for this study is to compare clinical treatments for patients with functional bowel disorders (irritable bowel syndrome, abdominal pain, painful constipation) in women. We also plan to: 1) determine what clinical features (medical or psychological) determine which patients will improve to these treatments, and 2) understand if there are any physiological features that relate to improvement in symptoms and response to the treatments. We will compare a psychological treatment (cognitive-behavioral therapy - CBT) with education/attention placebo, and an antidepressant drug (desipramine) with a pill placebo. This is the first large-scale study designed to determine the therapeutic effects of these methods, and to also determine interactions among physiologic measures, psychologic and sociodemographic factors, severity of symptoms, and therapeutic improvement including quality of life.

Female patients (aged 18-65) with FBD (irritable bowel syndrome, painful constipation and/or functional abdominal pain) will be enrolled at UNC-Chapel Hill and Toronto, Canada. A severity index will determine recruitment into the group of moderate FBD (200 patients) and severe FBD (100 patients). Each group will be randomized into the three treatment arms (cognitive-behavioral treatment, desipramine, and education/attention placebo), treated over a 12-week period, and followed for one year. Outcome measures will include symptoms (standardized abdominal pain, stool form and frequency) using diary cards, daily functional status (Sickness Impact Profile), depression (HAM-D) and psychological distress (SCL-90), physiological measures (enhanced rectal motility and visceral sensation), and health care use. Multivariate statistical methods with a hierarchical design will be applied to the data to assure maintenance of statistical power over multiple tests of overlapping groups. The results of this study should significantly improve our understanding of this complicated syndrome that lowers the quality of life and economic productivity of large numbers of women. The clinical impact of the study, in providing physicians with scientific evidence of the efficacy of treatments of FBD that are commonly used in practice, is significant. We anticipate that this study will provide clinicians with predictors of success among types of FBD patients and types of therapy that will improve symptoms and quality of life, and reduce the health care costs associated with this common syndrome while improving patient-physician satisfaction.