M1706 Discontinuation of Lubiprostone Treatment for Irritable Bowel Syndrome with Constipation Is Not Associated with Symptom Increase or Recurrence: Results from a Randomized Withdrawal Study

Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder with an estimated prevalence of 10–15% in Western countries. • Diagnosis of IBS is based upon the presence of abdominal discomfort/pain with changes in bowel habits. In clinical practice and research, IBS patients are • subgrouped on the basis of differences in bowel habits. Approximately 1/3 of IBS patients suffer with IBS and constipation (IBS-C). Current therapies for IBS-C tend to target relieving individual symptoms of constipation, abdominal pain or bloating rather than the totality of IBS symptoms. • Lubiprostone, a selective activator of type-2 chloride channels (CIC-2), is approved for the treatment of chronic idiopathic constipation in adults and for the • treatment of IBS-C in adult women. Lubiprostone enhances fluid secretion into the intestinal lumen without altering serum electrolyte levels. • Patients with IBS may exhibit abnormal gut permeability and an associated intestinal inflammatory response. Lubiprostone stimulates recovery of mucosal • barrier function in animal models suggesting a possible mechanism for the clinical improvement observed in patients on this drug.* Given the intermittent nature of IBS-C symptoms, short-term interventions for symptomatic relief of IBS-C may be appropriate in some patients. Such • interventions need to be efficacious and not associated with rebound effects following discontinuation of treatment.