With VC, the patient is given an oral contrast agent to increase the visibility of abnormal growths. The colon is inflated with carbon dioxide gas to make is easier to view. Patients may feel a mild degree of cramping, but most find the procedure more comfortable than a traditional colonoscopy. Patients do not require a sedative, so they can go home immediately after the procedure. To help doctors get a clear view of the colon, patients take a laxative at home prior to the test.
Many centers require patients to drink a gallon or more of laxative.
We have developed a simpler method that is better tolerated by most patients. The day before the exam, patients drink a liquid diet. The night before and morning of the exam, they drink 8 ounces of a laxative. On the exam day, they also drink three glasses of fluid mixed with a small amount of contrast agent. Early studies indicate that VC's accuracy is comparable to colonoscopy.