Prolonged visualization of the gastrointestinal tract with metrizamide.

Excellent images of the bowel can be obtained for many days, and sometimes weeks, after oral administration of metrizamide unless it is evacuated via the rectum or a bowel perforation; the quality of images obtained with barium or hypertonic contrast agents (such as diatrizoate meglumine and diatrizoate sodium) begins to deteriorate after several hours. The reasons for prolonged visualization of the bowel with metrizamide and its clinical applications are discussed.