Alan Alda and co-star Mike Farrell argued over the ethics of a surgery scene in Mash season 7, which was written into an episode. Farrell argued his character B.J. wouldn't take part in an unnecessary surgery, even if it involved saving lives. This clash between Farrell and Alda added tension and moral complexity to "Preventative Medicine."

A classic Mash episode was improved by a genuine argument between Alan Alda and a co-star over the ethics involved in a key surgery sequence. Many Mash actors exited the show during its early years, despite the medical sitcom becoming a runaway hit for CBS. These exits accidentally added to the show's longevity, since the ensemble was periodically refreshed with great new characters like Potter (Harry Morgan) or Major Winchester (David Ogden Stiers).

Wayne Rogers' Trapper left Mash following season 3, with the actor feeling his role kept being diminished by the increasing focus put on Alda's Hawkeye.