Depending on your circumstances, there may be other tests you can have.
These tests are all lower in cost compared to a colonoscopy, don’t usually require sedation and have less risk of complications. However, they do have limitations.
- Virtual colonoscopy using computed tomography (CT scan) produces multiple images of the inside of your colon. It’s less invasive and, unlike colonoscopy, it can also detect problems outside of the colon.
On the downside, it does use x-ray radiation, it can miss small polyps or lesions and you’ll still need to do a full bowel preparation. If a polyp or lesion is found, you’ll need to have a conventional colonoscopy at a later date to remove the polyp or to biopsy a lesion.
This procedure is done without sedation and, since your colon needs to be inflated with air, many patients find it uncomfortable.
- Flexible sigmoidoscopy is like colonoscopy but it only examines the lower part of the colon. The preparation is simpler than conventional colonoscopy. One disadvantage is that sometimes the part of the colon being examined is healthy, while there may be problems in the unexamined portion.
As with virtual colonoscopy, if a polyp or lesion is found, you’ll then need to have a conventional colonoscopy to remove the polyp, get a biopsy and examine the rest of your colon. Because of its limitations, flexible sigmoidoscopy is a rarely used alternative to colonoscopy.
- A barium enema is a type of x-ray of the bowel. Barium is a white contrast liquid that shows up on x-rays. Before having a barium enema you need to have bowel preparation, just as you would for colonoscopy. And you’ll need to have a conventional colonoscopy if a polyp or lesion is found. There’s some discomfort, but complications are rare, although barium enemas sometimes give false-positive results.