Twenty-four participants with non-constipation IBS and chronic abdominal pain will be recruited for enrollment. Participants will meet specific Rome III IBS diagnostic criteria.

Inclusion criteria:

* Participants will be 18-70 years of age.
* Participants will have non-constipation IBS \[that is IBS-D (diarrhea), IBS-M (mixed), or IBS-U (unspecified)\] with chronic abdominal pain diagnosed in their medical records at Mayo Clinic with chronic pain documented for ≥ 3 months.
* Participants will have subjective pain ratings of ≥ 30 on the 100 mm VAS during at least 1 of the 2 run-in weeks for enrollment.
* Participants will be capable of providing informed consent.

Exclusion criteria:

* Diagnosis of moderate-severe depression as per BDI ≥18;
* Alcohol or illicit substance dependence or abuse in the past 12 months;
* Dementia, unprovoked seizure history, seizure disorder;
* Pregnancy (all women of childbearing potential will be required to have a negative pregnancy test prior to initiation, and will be on a highly effective method of contraception, as detailed in the consent form);
* Significant change or increase in antidepressant or pain medications within the last four weeks; significant change in primary treatment interventions for pain in the past four weeks;
* Medically unstable
* Severe hepatic or renal impairment, such as baseline AST or ALT ≥ 2.5 X upper normal limit or end-stage renal disease with estimated glomerular filtration rate or creatinine clearance \<15mL/min. Although Rimegepant is rarely associated with abnormal circulating liver enzymes, we shall exclude patients with baseline AST or ALT equal to or greater than 2.5 times the upper limit of normal.
* Concomitant use of strong CYP3A4 inhibitors and strong or moderate CYP3A4 inducers.
* Participants who report nausea several times per week or daily on the baseline bowel disease questionnaire (question # 16) will be excluded from the study because of the low risk of nausea induced by the treatment which was estimated at approximately 3% for rimegepant compared to 1% for placebo.

Note: Other protocol defined Inclusion/Exclusion Criteria may apply.

Eligibility last updated 9/26/2024. Questions regarding updates should be directed to the study team contact.