This multinational, Internet-based survey was designed to assess the prevalence, frequency, severity, and impact of opioid-induced bowel dysfunction (OBD) in patients receiving opioid therapy for chronic pain and taking laxatives. In total, 322 patients taking daily oral opioids and laxatives completed the 45-item questionnaire. At the time of the survey, 45% of patients reported <3 bowel movements per week. The most prevalent opioid-induced side effects were constipation (81%) and straining to pass a bowel movement (58%). Those side effects considered most bothersome by patients were (in order of rank) constipation, straining, fatigue, small or hard bowel movements, and insomnia. Most of the OBD symptoms specified in the questionnaire were experienced by the majority of patients >or=4 times a week. Constipation was the OBD symptom that was most often reported as severe. Most patients reported that their OBD symptoms had at least a moderate negative impact on their overall quality of life and activities of daily living. A third of patients had missed, decreased or stopped using opioids in order to make it easier to have a bowel movement. The survey findings confirm that OBD occurs frequently, despite the use of laxatives, in individuals taking daily oral opioids for chronic pain. These gastrointestinal symptoms add to the burden already experienced by chronic pain patients, negatively impacting quality of life and, in some cases, affecting opioid treatment itself.