The purpose of this study is to determine if lubiprostone may change the rate of movement of food and activities in the stomach and intestines in subjects whose gastrointestinal (GI) tract is slower due to constipation.

To be able to measure the time difference in the duration of transit of the FDA approved SmartPill capsule in all segments of gastrointestinal (GI) tract before and after exposure to lubiprostone.

The investigators anticipate to capture the possibility to reduce/eliminate the small intestinal bacterial overgrowth in chronically constipated patients after administration of study drug- lubiprostone.

Lubiprostone is an effective treatment for chronic constipation. The mechanism of action of lubiprostone is through increasing fluid and mucus secretion and improving lubrication of the intestinal lumen. The effects of lubiprostone on gastrointestinal (GI) transit and small bacterial overgrowth (SIBO) have not been sufficiently explored.

The current study was designed to investigate whether: (a) lubiprostone alters GI transit and (b) affects SIBO in constipated patients.

Twenty nine female patients (mean age of 39 year: range 19-64) with chronic constipation received 2 weeks of lubiprostone (24 mcg b.i.d., P.O.). Stool consistency based on Bristol stool scale and the frequency of bowel movements were recorded. Gastric emptying time (GET), small bowel transit time (SBTT), colon transit time (CTT), combined small & large bowel transit time (SLBTT) and whole gut transit time (WGT) were measured using wireless motility capsule. Small bacterial overgrowth (SIBO) status was assessed by the lactulose breath test.

Inclusion Criteria:

• 18-65 years old

• At least a 6 months history of constipation. Constipation defined as follows:

  • Less than three complete spontaneous bowel movements per week and one or more of the following:

    1. At least 25% of stools are very hard and/or hard stools
    2. Sensation of incomplete evacuation following at least 25% of bowel movements.
    3. Straining on at least 25% of defecations. The above criteria are only applicable to spontaneous bowel movements. Patients who have no spontaneous bowel movements (bowel movements are preceded by laxative intake) are considered constipated and are eligible for this study.

• For patients ≥ 50 years of age, normal colonic anatomy as documented by colonoscopy, double-contrast barium enema, or flexible sigmoidoscopy performed within the previous 5 years.

Exclusion Criteria:

• Pregnancy or lactation.

• Subjects unwilling to practice adequate contraception throughout the period of screening through 14 days after the study termination.

• Use of laxatives 3 days immediately prior to randomization (except fiber or bulking agents).

• Use of any of the following drugs within 3 days prior to randomization:

  • Prokinetic agents (tegaserod, domperidone, cisapride, metoclopramide, erythromycin).
  • Medication containing opiates.
  • Anti-spasmodic (e.g., atropine, hyoscyamine, scopolamine, glycopyrrolate).

• Use of illegal drugs

• Regular consumption of 2 drinks of alcohol per day.

• Chronic nonsteroidal antiinflammatory drugs (NSAIDs) use

• Chronic use of H2 receptor antagonist or proton pump inhibitors (PPIs) within 14 days prior to screening.

• History of gastric or duodenal ulcer, inflammatory bowel disease(IBD), or chronic non-ulcer dyspepsia.

• Diabetes Mellitus (DM) type 1, Parkinson's disease.

• Existence of any medical condition that requires chronic therapy.

• Positive H. pylori serology

• Chronic active diverticulosis