Effect of Lubiprostone on Small Bowel Contractions in Female Patients With Constipation Irritable Bowel Syndrome (C-IBS)

Irritable Bowel Syndrome (IBS) is a common disorder, defined by symptom-based diagnostic criteria. The pathogenesis is multifactorial and gut motor dysfunction is considered to be a contributing factor. Changes in motor patterns in the small bowel in IBS patients are quantitative rather than qualitative with no distinct patterns to distinguish patients from healthy individuals. Changes in motor patterns can affect transit of bowel contents. Indeed, variation in intestinal transit was reported in patients with IBS. Lubiprostone is a novel agent that is Food and Drug Administration (FDA) approved for the treatment of chronic constipation. More recently 2 randomized double-blind, placebo-controlled trials showed the drug to be effective in relieving symptoms in patients with constipation-predominant Irritable Bowel Syndrome (C-IBS), resulting in approval for female patients with C-IBS at a dose of 8 micrograms twice a day. The investigators hypothesize that lubiprostone works not just as a laxative, but by actually altering motility patterns in the small intestine of female patients with C-IBS. These alterations can be measured through High Resolution Manometry (HRM), a new technique that uses catheters with multiple closely spaced sensors and special software that uses color schemes to portray a pressure gradient. This technique allows a detailed assessment of the direction and spread of contractions. The investigators would like to use HRM to see if lubiprostone affects intestinal contractions by giving blinded participants lubiprostone and placebo while they are undergoing High Resolution Manometry and seeing if any changes in contractions occur. Participants will be recruited from investigator's clinic. If interested, potential subjects will be provided with a copy of the consent form for review. Patients will be informed that after they have had an opportunity to review the consent form, they may contact the study team to further discuss the research and address any questions/concerns they have. Participants will undergo a screening visit and a manometry visit. During the screening visit investigators will determine eligibility, including application of inclusion/exclusion criteria and administration of a pregnancy test. Then during the manometry visit patients will receive two capsules, lubiprostone and placebo, three hours apart during HRM. Patients will receive each capsule only once and will not know which order they're receiving them in.