Both the TV show and movie of M.A.S.H. deserve many criticisms, but I believe that we should be correct in the particulars.
The lyrics of "Suicide is Painless" refer to the dentist himself (nicknamed "Painless"), who, despondent over an episode of impotence, fully intended to commit suicide.
The surgeons, realising the temporary nature of his problem, gave him pills that would simply sedate him, then talked a nurse into seducing him when he awakened.
The song starts out with these lines-
"Suicide is Painless
It causes many changes"
Pretty truthful- the rest of the lyrics are mostly nonsense as far as I can tell. I must say, though, that I've always found the music to be beautiful and haunting.
For what it's worth, my father spent some time recupurating in a M.A.S.H. unit during the Korean way- he says that they were just as professional as any hospital or military unit.
I stand corrected; I was quoted from my old, creaky, memory.
And it was prob'ly past my bedtime as well :-)
In any case, can we agree Alan Alda was a flaming metrosexual?
Cheers!