The Role of Intestinal Inflammation in Irritable Bowel Syndrome (IBS) (K23)

Inclusion Criteria:

• Any sex, race, or ethnicity.
• At least 18 years of age (no upper age limit).
• D-IBS and M-IBS patients must meet Rome II criteria for IBS and must have been evaluated by a physician to exclude alternative diseases that could explain the symptoms. For the latter, patients' self statement is acceptable (by self-report, no official document is required).
• D-IBS and M-IBS subjects older than 50 years old must have had a colonoscopy in the past 5 years with a normal report. Hemorrhoids, diverticulosis and polyps are allowed.
• Participation in Dr. Whitehead's heterogeneity of IBS research study, or Dr. Ringel's Probiotic Pain Study.

Exclusion Criteria:

• Healthy controls must have no significant or recurring gastrointestinal symptoms.
• Patients and healthy controls should not have a serious, unstable medical condition.
• Patients and healthy controls must have had no gastrointestinal tract surgery other than appendectomy or cholecystectomy, or any abdominal surgery within the past 3 months. Appendectomy and cholecystectomy are allowed if done more than 2 years ago and symptoms were not changed following the surgery.
• Pregnancy and breastfeeding (by self-report).
• No history of inflammatory bowel diseases, celiac disease, or other diagnosis that could explain chronic or recurring bowel symptoms in IBS patients or controls (by self-report).
• Patients and controls should have no history of lactose malabsorption (by self-report).
• Patients and controls should have no history of clinical symptoms of acute infections during the last 8 weeks prior to enrollment in the study.
• Patients and controls should have no history of anti-inflammatory agents including aspirin, non-aspirin, non-steroid anti-inflammatory (NSAID), steroids, antibiotic, or probiotics treatment during the last 4 weeks prior to enrollment in the study.
• Patients should not have an implanted or portable electro-mechanical medical device such as a pacemaker and/or other implanted stimulators or pumps.
• Evidence of acute inflammation on routine histology.
• Evidence of enteric pathogens on routine stool cultures.
• Presence of a medical condition that requires routine use of antibiotic treatment with dental or other invasive procedures (by self-report).
• To be confirmed at time of screening and the week of the flexible sigmoidoscopy appointment for IBS-M subjects ONLY: In the past week, subject cannot have less than 3 (0-2) bowel movements. Also, in the past week, subject cannot have hard/lumpy stools for 2 or more days.

Only subjects with IBS may participate in the optional SmartPill testing. Subjects are excluded from SmartPill testing if a subject has:

• A history of gastric bezoar.
• Suspected strictures, fistulas, colon cancer or other physiological GI obstruction.
• Dysphagia.
• Diverticulitis.
• Tobacco use within eight hours prior to capsule ingestion and during the initial 8 hour recording on Day 0 or the Ingestion visit.
• Alcohol use within eight hours prior to capsule ingestion and throughout the entire monitoring period (5 days).
• Body Mass Index > 40 kg/m2.
• Female of childbearing age who is not practicing birth control and/or are pregnant or lactating.
• Cardiovascular, endocrine, renal, or other chronic disease likely to affect motility.
• A medical device such as a pacemaker, infusion pump, or insulin pump.
• Any contraindication to use of Fleets Enema or the balloon expulsion test.
• Uncontrolled diabetes with a hemoglobin A1C greater than 10.
• Allergies to any of the ingredients of the standard SmartBar meal
• Subject plans to take any of the following prohibited medications: Medication to alter gastric pH, Medication that affect GI motility for 3 full days before the start of the study and during the ensuing days of study, Medication for nausea and vomiting that block serotonin receptors, Anti-diarrheal agents, Opiate agents used to treat diarrhea, Non-steroidal anti-inflammatory drugs