It makes me think of a couple of films:
"Bobby" segment in "Dead of Night" (1977 TV movie) and "Trilogy of Terror II" (1996 TV movie)
In both versions, a mother summons her son back from the dead, but he returns quite different than she expects.
If it was a girl...
The Dark (2005)
In this, the girl falls into the ocean and is taken to Annwyn, a place in Welsh mythology. The mother must go there to try to retrieve her.
Those are the only possibilities I can think of right now.