“The advent of a prepackaged sterile carbon particle suspension (Spot, GI Supply, Camp Hill, PA) has greatly enhanced the accessibility and ease of use of endoscopic tattooing. Concurrently, the indications for colonic tattooing expanded beyond marking of carcinomas to also encompass endoscopic localization of difficult-to-detect polyps, polypectomy sites, or dysplastic areas for future colonoscopic surveillance or therapy.”
Moss, A. Colonic tattooing: the revival of a black art? Gastrointest Endosc. 2012 Oct;76(4):801-3.