Key messages

• Using linked color imaging during colonoscopy is more effective than traditional procedures at identifying growths that can turn into cancer.

• Both linked color imaging and traditional colonoscopies have the same small chance of side effects, and these problems rarely occur.

• More research is needed to understand (1) how many adults who have linked color imaging colonoscopy are diagnosed with colorectal cancer at their next follow-up colonoscopy, (2) whether linked color imaging helps lower cancer rates at that next follow-up compared to standard colonoscopy, and (3) whether linked color imaging causes any serious side effects that need medical treatment—something only larger studies can reveal.

Background

Colonoscopy is an important procedure for checking for colon cancer, monitoring colon health, investigating colon-related symptoms, and identifying and treating certain types of growths (or polyps) that can lead to cancer. These include adenomas (small, non-cancerous growths that can become cancer) and sessile serrated lesions (flat or slightly raised polyps with a saw-toothed appearance). The procedure involves inserting a narrow flexible tube with a tiny camera and light on the end into the rectum. Linked color imaging colonoscopy uses various light colors to detect tumors (any abnormal growth that can be non-cancerous [benign] or cancerous). Doctors performing colonoscopies can switch between regular white light and the color-based view with a button press if they use a specific system.

What did we want to find out?

We wanted to find out whether linked color imaging or traditional colonoscopy with normal white light is better and safer for people undergoing colonoscopy.

What did we do?

We searched for studies comparing linked color imaging with traditional colonoscopy. We compared and summarized the results of the studies and rated our confidence in the evidence, based on factors such as study methods and sample sizes. We investigated the adenoma detection rate (defined as the proportion of colonoscopies in which at least one adenoma was detected during the study period), the proportion of participants with colorectal cancer diagnosed by the next recommended date of examination after a negative colonoscopy, and side effects requiring medical treatment. In addition, we evaluated the polyp detection rate, sessile serrated lesion detection rate, and number of adenomas per participant.

What did we find?

We identified 16 studies involving 12,836 participants that compared linked color imaging and traditional colonoscopy.

Main results

Compared with traditional colonoscopy, linked color imaging:

• increases adenoma detection rate slightly;

• probably makes little to no difference in side effects requiring medical treatment;

• increases polyp detection rate slightly;

• probably increases sessile serrated lesion detection rate slightly; and

• probably increases the number of adenomas per participant slightly.

None of the studies assessed the proportion of participants diagnosed with colorectal cancer by the next recommended date of examination after a negative colonoscopy.

What are the limitations of the evidence?

We are confident in the evidence about adenoma and polyp detection rates. Our confidence in the evidence for the other outcomes is only moderate because the studies included too few participants to be sure about how well linked color imaging finds sessile serrated lesions and how many adenomas each person has. Similarly, because none of the people included in the studies had side effects requiring medical treatment, we cannot tell how often such problems might occur. In addition, none of the studies reported how many people developed colorectal cancer at the next recommended check, so we cannot draw any conclusions about that outcome.

How current is this evidence?

The evidence is current to May 2025.