With limited efficacy of medications for symptom relief, non-medication treatments may play an important role in the treatment of irritable bowel syndrome (IBS), the most common functional gastrointestinal (GI) disorder. This study aimed to evaluate the efficacy of two self-regulation strategies for symptom relief and mood management in IBS patients. Thirty-five adult participants meeting ROME III criteria for IBS were enrolled, 27 of the 35 participants (77%) completed treatment and pre- and post-treatment visits (89% women, 11% men; M (SD) age = 36 (13)), and 20 of the 27 (74%) completed a 6-month follow-up. Participants were randomly assigned to 16 biweekly group sessions of Iyengar yoga or a walking program. Results indicated a significant group by time interaction on negative affect with the walking treatment showing improvement from pre- to post-treatment when compared to yoga (p < .05). There was no significant group by time effect on IBS severity. Exploratory analyses of secondary outcomes examined change separately for each treatment condition. From pre- to post-treatment, yoga showed significant decreases in IBS severity measures (p < .05), visceral sensitivity (p < .05), and severity of somatic symptoms (p < .05). Walking showed significant decreases in overall GI symptoms (p < .05), negative affect (p < .05), and state anxiety (p < .05). At 6-month follow-up, overall GI symptoms for walking continued to significantly decline, while for yoga, GI symptoms rebounded toward baseline levels (p < .05). When asked about self-regulated home practice at 6 months, significantly more participants in walking than in yoga practiced at least weekly (p < .05). In sum, results suggest that yoga and walking as movement-based self-regulatory behavioral treatments have some differential effects but are both beneficial for IBS patients, though maintenance of a self-regulated walking program may be more feasible and therefore more effective long term.