I try to drink lots of water but I also have a pill that helps me stop bloating. It has corn silk in it. I'd have to look at the bottle to remember what it's called.
Walk around. And massages help too elevate your feet and massage them then get up and walk around for a bit. This happened to me when I was hospitalized during my last pregnancy I swelled up like crazy from 8 bags of IV fluids they gave me.