Effects of Lubiprostone on Gastrointestinal Transit & pH in Irritable Bowel Syndrome (IBS) With Constipation
Status:
Completed
Trial end date:
2012-12-01
Target enrollment:
Participant gender:
Summary
Irritable bowel syndrome (IBS) is a common disorder which presents with abdominal pain or
discomfort in association with altered bowel habit. IBS is further subcategorized as three
types according to the predominant bowel movement pattern: IBS with constipation (IBS-C), IBS
with diarrhea (IBS-D), and mixed-IBS (IBS-M). The exact causes of IBS remain incompletely
understood, but proposed mechanisms include abnormal motility, visceral hypersensitivity,
abnormal brain-gut interactions, psychological distress, and altered GI tract motility.
Lubiprostone, a novel drug that works by activating the colonic Chloride channel type
2(ClC-2), has been approved for use in patients with chronic idiopathic constipation and
recently approved for the treatment of IBS-C in women aged 18 and older. By activating the
ClC-2 chloride channel in the colon, lubiprostone allows more fluid secretion into the
intestinal lumen which leads to softer stool consistency. In phase III clinical trials,
patients with IBS-C receiving lubiprostone have reported improvements in many symptoms such
as abdominal pain and constipation. However, there is limited physiologic data to explain how
exactly lubiprostone improves IBS-C symptoms.
The Smartpill is a novel non-digestible capsule that is capable of measuring intraluminal pH,
pressure, and temperature in the gastrointestinal (GI) tract. Smartpill has been shown to
accurately measure whole gut as well as regional (i.e. stomach, small bowel, colon) transit
time.
The primary aim of this study is to determine the effects of lubiprostone on whole GI tract
transit, colonic transit, motility, and intraluminal pH in patients with IBS-C through
evaluation with the Smartpill. The investigators propose to study the effect of lubiprostone
vs. placebo on these parameters, and secondarily to evaluate changes in these parameters with
differing doses of lubiprostone.
The investigators hypothesize that lubiprostone will increase whole GI and colonic transit
compared to placebo in patient with IBS. the investigators do not expect a change in
intraluminal pH with lubiprostone compared to placebo.