Marking and identifying colon lesions. Tattoos, clips, and radiology in imaging the colon.

Precise knowledge of a lesion's location in the colon is infrequently required. Occasionally, however, this information can be of critical clinical importance. A variety of endoscopic and radiologic techniques have been described to localize an area or site within the colon. Tissue staining or tattooing is the most reliable endoscopic method of colon lesion localization, and India ink provides a long-lasting and probably permanent tattoo of the site. Endoscopic clips are less reliable and remain cumbersome to use. Electronic imaging is an intriguing approach but remains experimental. Sites and lesions also can be identified by barium radiography or fluoroscopy, but these techniques involve added expenses and are not as reliable as tattooing with India ink.