Data from the US military's Millennium Cohort Study was used to examine risk factors for new-onset IBS among military personnel on active duty in a new study published in The American Journal of Gastroenterology. 41,175 cohort members were included in the study, and 314 new-onset cases of IBS were identified. Risk factors included previous case of infectious gastroenteritis, number of life stressors, female sex and anxiety syndrome. Importantly, anxiety or depression in combination with infectious gastroenteritis was found to increase the risk of subsequent IBS compared with infectious gastroenteritis alone.