If you have ever watched a gastroenterologist spray blue dye inside someone’s colon, you might wonder whether we have moved past that particular era of medicine. The procedure is messy, it adds time, and it requires a level of patience that not every endoscopy schedule can accommodate. So when camera manufacturers began building sophisticated lighting modes directly into their scopes electronic filters that enhance the bowel surface in real time, no dye required the appeal was obvious. Quicker, cleaner, and arguably more elegant.

The question we set out to answer was simple: does the elegant option work just as well?

Why this matters

Patients with inflammatory bowel disease ulcerative colitis or Crohn’s disease affecting the colon carry a significantly higher risk of developing bowel cancer than the general population. The longer someone has lived with colitis, the higher that risk climbs. Unlike typical bowel polyps, which tend to be raised and easy to spot, the early cancerous changes in IBD patients are often flat, subtle, and camouflaged by years of chronic inflammation and scarring. Missing them can have devastating consequences.

This is why surveillance colonoscopy exists: regular check-ups with a camera to catch dysplasia the precancerous changes before they progress. And this is where the debate about dye versus electronic imaging becomes more than academic. If the newer technology misses even a few of these flat, hard-to-see lesions, the clinical implications are real.

What we did

Over three years at Al Adan Hospital in Kuwait, we enrolled 300 patients with IBD who were due for their surveillance colonoscopy. Each patient was randomly assigned to one of two groups. In the first group, we sprayed methylene blue dye onto the bowel lining during the procedure a technique called dye-based chromoendoscopy. In the second group, we used Fujifilm’s built-in electronic lighting modes, Blue Light Imaging (BLI) and Linked Color Imaging (LCI), which enhance mucosal detail digitally without any dye.

Crucially, every single procedure was performed on the same camera system the Fujifilm ELUXEO platform by the same endoscopist. This eliminated two of the biggest confounders that plague comparative studies: differences between camera brands and differences between operators. Whatever we found, we could be confident it reflected the techniques themselves, not the equipment or the person holding the scope.

What we found

Dysplasia was detected in 10% of our patients overall 30 out of 300. But the detection rate was not evenly split. The dye group picked up dysplasia in 12% of patients, compared with 8% in the electronic imaging group. That 4% absolute difference may sound small, but it represents a 50% relative increase in detection meaning for every two cases the camera lighting found, the blue dye found three.

Where it got really interesting was in the pattern of what was being missed. The extra lesions detected by the dye method were overwhelmingly flat (not raised) and located in the right side of the colon precisely the type of dysplasia that is hardest to see and most dangerous to miss. Electronic imaging performed comparably for polypoid, raised lesions, but its advantage disappeared when the target was subtle and flat.

We also found that certain patients were at particularly high risk: those with disease lasting more than ten years, those with inflammation throughout the entire colon, those with a liver condition called primary sclerosing cholangitis, and those on advanced immunosuppressive or biologic therapies. In these high-risk groups, the argument for dye-based chromoendoscopy was even stronger.

What this means for clinical practice

Our findings do not mean that electronic imaging has no role. For lower-risk patients those with shorter disease duration, limited colitis, no additional risk factors, and a healed bowel lining virtual chromoendoscopy is a reasonable and practical option, particularly in busy endoscopy units where dye-based techniques are logistically challenging. But for patients who carry multiple risk factors, our data suggest that the blue dye is still worth the mess.

This is consistent with the most recent international evidence. Two major meta-analyses published in 2024 and 2025, incorporating thousands of patients across dozens of trials, have both concluded that dye-based chromoendoscopy remains the most sensitive technique available for detecting dysplasia in IBD surveillance. Our study adds something these pooled analyses could not provide: platform-specific evidence from the Fujifilm system, tested head-to-head in a controlled setting.

Looking ahead

The next frontier is artificial intelligence. Early studies have shown that AI-assisted detection systems can significantly improve sensitivity for IBD-related dysplasia, particularly for the flat and subtle lesions that both human eyes and electronic imaging struggle with. Whether AI will eventually level the playing field between dye and electronic techniques or even surpass both is an exciting question that future studies will need to answer.

In the meantime, our message to clinicians is pragmatic: know your patient’s risk profile, and choose your surveillance tool accordingly. For the highest-risk patients, dye-based chromoendoscopy continues to offer something that electronic imaging, in its current form, does not fully replicate and that something may be the difference between catching dysplasia early and missing it entirely.