This variable is part of the Abdominal Pain section of the Digestive Disease Supplement, introduced in the 1989 survey. This supplement focuses on digestive conditions, primarily during the previous 12 months, to provide data for prevalence estimates on certain common digestive disorders and complaints. The Abdominal Pain section provides data to compare diagnosed and undiagnosed irritable bowel syndrome, and to describe pain accompanying this or other conditions that affect the abdomen.