Shelby hurled more often when she was younger, rarely anymore. (morning bile) It seemed to happen on an empty stomach the day after she ate too many gunks. carpet pieces, dust balls, dried worms, brick, wood, cement...
but she doesn't eat her poop YAY
Now I keep her gated in small areas of my house so she can't get to anything "extra" on the floor. I can't let her in the backyard without backup to help me control her. Makes me crazy.
I found that if I limit her gunk intake
and feed her FOOD immediately in the morning, the hurling stops. I talked to the vet about it and she said it happens sometimes, may have acid stomachs like some humans. she suggested giving her a little plain yogurt at bedtime, then feeding her early in a.m.
if it is food he is vomiting up I don't know what causes that.
good luck