In It, by Stephen King, Henry Bowers follows the Losers into the sewers in 1958. They defeat It, and escape the sewage after a strange out-of-context orgy.
They never meet Henry again. How does he find his way out of the sewers if even the Losers, guided by Eddie's intuition, had trouble doing so?
I don't think this is ever addressed in the book. As far as I know, the closest thing to a canon answer comes during the Chinese Restaurant scene in the TV series. In a brief discussion of Henry Bowers, Bill says
I remember when they pulled him out, his hair had turned white.
Presumably, 'they' refers to the authorities (police/fire & rescue/sewer maintenance crews, etc.). So, in the TV series at least, he is rescued.
