ABSTRACT
Lasers have been produced employing various designs and base materials, and new technology is continuing at a rapid rate to find medical applications. The three main types of lasers used in the lower gastrointestinal (GI) tract are carbon dioxide (CO2), argon, and neodymium:yttrium-aluminum-garnet (Nd:YAG) lasers (Table 1). The different wavelengths determine the visibility of the beam, depth of tissue penetration, and ultimately, the desired tissue effect to be obtained clinically. This varies from coagulation, vaporization, cutting, localized hyperthermia, and photodynamic therapy. Each of these biological actions has specific applications in the lower tract (Table 2), which are related to the interaction of laser light on the living tissue (Table 3).
