This is a retrospective clinical study with prospectively designed blinded evaluation of CT images in adult and pediatric patients who underwent CT examinations of the abdomen and pelvis and were orally administered a solution of Isovue-300 to opacify the GI tract to distinguish it from adjacent abdominal and pelvic structures. The study will collect already existing data, such as demographic data, adverse events and CT images, for all chronologically enrolled patients who meet the inclusion/exclusion criteria prospectively defined in this protocol

Patients will be included in the study if:

• Demographic and safety data are available for analysis
• Complete set of CT images performed after oral administration of Isovue-300 are available for assessment
• Isovue-300 was orally administered during an interval time of 60-20 minutes before the CT scanning.

Patients will be excluded from the study if:

• Oral contrast agent received within 1 week prior to the CT scan
• Undergone any abdominopelvic surgery procedure that resulted in alteration of the bowel transit time prior to the CT exam
• CT exam with oral administration of Isovue was performed because of a known or suspected condition of bowel obstruction
• Patient did not actively drink the contrast solution.

Adult and pediatric patients who have previously undergone CT examination of the abdomen and pelvis with oral administration of Isovue-300 (2-3% concentration) as part of their clinical work-up.