Virginia Subscriber
Answer: You can only bill anesthesia for one procedure, even if multiple procedures are performed during the same session.
When multiple procedures are performed, you report anesthesia based on the higher-base procedure. In this case, that means you code for the hemicolectomy with a general anesthetic instead of the colonoscopy with MAC.
Report code 00840 (Anesthesia for intraperitoneal procedures in lower abdomen including laparoscopy; not otherwise specified), which is six base units plus time.
Even though you're only coding for one procedure, you do report the total amount of time associated with both procedures.