X-rays of the abdomen are important in diagnosing the presence of small bowel obstruction. When obstruction occurs, both fluid and gas collect in the intestine. They produce a characteristic pattern called "air-fluid levels". The air rises above the fluid and there is a flat surface at the "air-fluid" interface.
Review Date 4/30/2020
Updated by: Bradley J. Winston, MD, board certified in gastroenterology and hepatology, Washington, DC. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.