Objectives: An international multicenter, prospective, non-interventional, 2-month study characterized acute pain attacks in patients with irritable bowel syndrome (IBS). Methods: Adult patients meeting the Rome III IBS diagnostic criteria with a history of 3 pain attacks per month participated in a survey that captured daily and episodic information regarding IBS symptoms and pain attacks for 2 months. Acute pain attacks were defined as a sudden onset or increase in the intensity of IBS abdominal pain with a minimum intensity of 4 (0-10 scale). Results: The majority (84%) of the 158 patients taking the survey were women with a mean age of 41 years and time since IBS diagnosis of 5 years. The median pain attack frequency was 5.4 attacks per month and was significantly higher in the IBS with diarrhea (IBS-D, 6.4 per month) group vs. the IBS with constipation (4.4 per month) and the IBS with mixed pattern (5.5 per month) groups (P