What Is a Chromoendoscopy?

This Chromoendoscopy helps visualize the inner surface of the bowel (epithelia) during endoscopy.

A chromoendoscopy is a diagnostic procedure in which a chemical substance (called a stain or pigment) is sprayed inside the gut to highlight specific areas or distinguish among the different types of cell layers. This helps visualize the inner surface of the bowel (epithelia) during endoscopy. Chromoendoscopy is a simple, cost-effective, quick, and safe diagnostic method that improves the recognition of the tiny changes in the surface pattern. It does this by enhancing the contrast of raised and deepened areas. 

Three types of stains can be used for chromoendoscopy:

• Absorptive or vital stains: These stains diffuse or are selectively absorbed across specific epithelia (e.g., Lugol's solution and methylene blue).
• Contrast stains: These stains highlight surface irregularities (topography) of the inside of the gut by filling the mucosal crevices (e.g., methylene blue).
• Reactive stains: As the name suggests, these stains undergo chemical reactions with specific cell components, resulting in a color change (e.g., congo red and phenol red).

A chromoendoscopy may be done to diagnose:

• Barrette esophagus: A condition in which the normal, flat pink lining of the food pipe (esophagus) becomes thickened and red because of the damage caused by acid reflux
• Cancer of the esophagus
• Stomach cancers
• Gut polyps: Small clump of cells formed on the lining of the gut, especially the colon
• Cancer of the intestine (bowel)
• Inflammatory bowel disease (IBD): A medical conditions which involve chronic inflammation of the digestive tract or gut (e.g., ulcerative colitis and Crohn’s disease)
• A chromoendoscopy may be used along with other advanced endoscopic imaging techniques such as magnification endoscopy, confocal endomicroscopy and confocal endocytoscopy

A chromoendoscopy may be used for treatment approaches like:

• Endoscopic mucosal resection
• Photodynamic therapy 

A chromoendoscopy is avoided if there is a history of an allergy to the dye or stain used for the procedure.

An ulcerative colitis is a type of inflammatory bowel disease (IBD), a condition in which there is long-term inflammation of the large intestine (colon) with peculiar sores or ulcers in the inner lining of the colon. The condition may involve severe diarrhea, pain in the abdomen, loss of appetite, fatigue, fever, and weight loss.

An ulcerative colitis increases the risk of cancers of the colon and rectum. A chromoendoscopy helps monitor the signs of progression toward cancer. In this technique, a dye is sprayed via an endoscope inside the gut which helps the doctor see which parts are affected by the ulcerative colitis. It enables the visualization of the inside of the colon and takes targeted biopsies. It also helps the doctor provide early management for the prevention of the development of cancer and if cancer has developed, to treat it at an early stage. Besides better visualization, the procedure has the advantage of being accurate, safe, quick and less expensive for monitoring or surveillance in case of an ulcerative colitis.