Patients with irritable bowel syndrome (IBS) often report higher levels of psychological distress, specifically anxiety, and depression than non-IBS patients. The management of gastrointestinal symptoms and psychological distress is demonstrably amenable to cognitive–behavioral therapies in a significant number of patients with IBS. The present secondary analysis evaluates the impact of nurse-delivered self-management interventions on anxiety, depression, and urine catecholamine levels in adult IBS patients. Participants in the study were randomized to 2 intervention groups of either comprehensive self-management (CSM) intervention or usual care control. Daily diary ratings of gastrointestinal symptoms, anxiety, and depression were recorded every evening for 28 days during the baseline period and subsequently at 3, 6, and 12 months postrandomization. Catecholamine levels of epinephrine and norepinephrine were measured from 4 weekly 1st morning urine samples at baseline as well as at each follow-up time. The CSM group reported significantly lower levels of anxiety and depression at follow-up than the usual care group (p = .018 and .021, respectively). In contrast, urine catecholamine levels displayed no appreciable change. Thus, although nurse-delivered CSM interventions showed no impact on urinary catecholamine levels, daily psychological distress was measurably reduced.