The primary goal of this study is to test the efficacy of emotional awareness and expression training (EAET), a novel emotional processing intervention that the investigators have developed, for people with IBS. In this randomized, controlled trial, the investigators will compare EAET to a standard intervention that teaches the conceptually opposite approach—relaxation training (RT)—and test how both of these interventions compare to a wait-list control condition. The investigators hypothesize that individuals in the EAET group will demonstrate greater improvement in their IBS symptom severity, psychological functioning, quality of life, and health care utilization at 4 and 12-week follow-up time points, compared to individuals in the wait-list control group. It is also expected that both of the active interventions (EAET and RT) will be more efficacious than the wait-list control condition.