While preparations for VC vary, the patient will usually be asked to take laxatives or other oral agents at home the day before the procedure to clear stool from the colon.

This allows the physician (usually a consultant radiologist), viewing the 3D images to effectively subtract the left-over faeces, which may otherwise give false positive results.

As a result, no sedation is needed, and the patient can return to his/her usual activities or go home after the procedure without the aid of another person.

VC provides clearer, more detailed images than a conventional x-ray using a barium enema, sometimes called a lower gastrointestinal (GI) series.

Optical colonoscopy is taken as the "gold standard" for colorectal cancer screening by the vast majority of the medical and research communities.

Virtual colonoscopy is favored by some professionals because it permits complete visualization of the entire colon, hence providing more opportunity to identify precancerous polyps and cancer, and to then do prompt diagnostic biopsies or therapeutic removal of these lesions.