LOTRONEX® in Severe Diarrhea-Predominant Irritable Bowel Syndrome (IBS-D) (RELIANCE)

• Change in stool consistency [ Time Frame: At Week 4 and Week 12 ] [ Designated as safety issue: No ]
  Stool consistency as measured by the Bristol Stool Form Scale. Change from baseline at Weeks 4 and 12 will be determined.
• IBS pain severity [ Time Frame: At Weeks 4 and 12 ] [ Designated as safety issue: No ]
  Pain intensity as measured by the 11-point numeric rating scale (NRS) will be averaged for each 4-week interval. Change from baseline at Weeks 4 and 12 will be determined.

• Change from baseline in quality of life scores (IBSQOL). [ Time Frame: Week 12 ] [ Designated as safety issue: No ]
  Change from baseline in IBSQOL scores will be calculated at Week 12.
• Change from baseline stool frequency. [ Time Frame: Week 4 and Week 12 ] [ Designated as safety issue: No ]
  Stool frequency will be measured as the mean number of times per day that stools were passed, and will be averaged for each 4-week interval. Change from baseline at Weeks 4 and 12 will be determined
• Change from baseline in fecal urgency. [ Time Frame: Week 4 and Week 12 ] [ Designated as safety issue: No ]
  Proportion of days with fecal urgency will be calculated for each 4-week interval and change from baseline will be determined at 4 and 12 weeks.
• Change from baseline in lost productivity. [ Time Frame: 12 Weeks ] [ Designated as safety issue: No ]
  Lost workplace productivity and number of days IBS symptoms interfered with social/leisure and household activities will be determined at baseline and week 12. Change from baseline to week 12 will be calculated.

An observational study to evaluate LOTRONEX® in women with severe IBS-D in the current clinical practice setting.

This observational study will evaluate the effect of Lotronex® as used in the current clinical practice setting on symptom relief, specifically, improvement in bowel habits and IBS pain. Patients planning to initiate commercially available LOTRONEX® therapy will be consented for study participation. Patients will complete study questionnaires related to bowel symptoms, prior therapies, quality of life, productivity loss and treatment outcome. Investigators will also be asked to complete questionnaires related to the patient's disease characteristics, patient progress on study medication and treatment outcome.

Women ≥ 18 years of age with severe diarrhea-predominant IBS, who have chronic IBS symptoms lasting 6 months or longer and who have not responded adequately to other IBS therapy will be eligible to enroll in the study.

Inclusion Criteria:

1. Be a female between 18 and 65 years of age (inclusive) at Visit 1.
2. Sign and date a written informed consent form prior to the initiation of any study-related activities, including discontinuation of any prohibited medications.
3. Be diagnosed with severe, diarrhea-predominant IBS.
4. Have experienced chronic IBS symptoms lasting 6 months or longer.
5. Have not responded adequately to other IBS therapy.
6. Be able to read, understand and sign the informed consent and, if applicable, an Authorization to Use and Disclose Protected Health Information form (consistent with Health Insurance Portability and Accountability Act of 1996 [HIPAA] legislation), answer the study questionnaires, communicate with the investigator, and understand and comply with protocol requirements.

Exclusion Criteria:

1. Has had a period of 3 consecutive days without a bowel movement in the past 14 days.
2. In the past 14 days, has had evidence of chronic or severe constipation, or has a history of chronic or severe constipation, or a history of sequelae from constipation.
3. Has recurrent bowel obstruction of the small intestine or colon.
4. Has had bloody diarrhea or abdominal pain with rectal bleeding in the past 14 days (except rectal bleeding due to hemorrhoids).
5. Has a known biochemical or anatomical abnormality of the gastrointestinal tract.
6. Has a history of thrombophlebitis or hypercoagulable state.
7. Has a history of atherosclerosis.
8. Has any medical or surgical condition that in the judgment of the investigator makes the patient an inappropriate candidate for Lotronex® therapy (e.g., an unstable cardiovascular, autoimmune, renal, hepatic, pulmonary, endocrine, metabolic, gastrointestinal, hematologic, or neurological condition; recent or ongoing malignancy; evidence of hepatic dysfunction; or renal impairment.)
9. Mental impairment of inability to understand the medication guide and instructions for study participation or refusal to comply with protocol.
10. Current (within 7 days from start of Lotronex® use) use of fluvoxamine.
11. Chronic (≥ 6 months) use of narcotics or opioids.
12. The patient has used an investigational drug or participated in an investigational study within 30 days of Visit 1/ Screening Visit.
13. The patient is hypersensitive or has a known negative response to 5-HT3 antagonists.
14. Had a significant adverse event during previous treatment with Lotronex® or is currently using Lotronex®.