Question:What is an anorectal biopsy, and how should I report it?
Answer:The code will depend on two things:
the instrument your gastroenterology used to obtain the biopsy and the biopsy's depth.
For instance, if the gastroenterologist used an anoscope to obtain a surface biopsy, you'll report 46606 (Anoscopy with biopsy) or if she used a proctosigmoidoscope, then use 45305 (Proctosigmoidoscopy with biopsy).
Your gastroenterologist could also perform an anorectal biopsy during a flexible sigmoidoscopy (45331, Sigmoidoscopy, flexible; with biopsy, single or multiple) or during a colonoscopy (45380, Colonoscopy, flexible, proximal to splenic flexure; with biopsy, single or multiple).
If this was a surgical procedure for a deeper biopsy, the gastroenterologist might have meant 45100 (Biopsy of anorectal wall, anal approach [e.g., congenital megacolon]), which describes a biopsy of the anorectal wall from an anal approach. Your physician could also describe this as a "suction biopsy." Usually, pediatric gastroenterologists perform this procedure to diagnose Hirschsprung's disease or congenital megacolon.
Note: Code 45100 has a 90-day global surgery package. If the physician has to go back to obtain more tissue during the global days, you should attach modifier 58 (Staged or related procedure or service by the same physician during the postoperative period) to the repeat biopsy code.