Assuming you've removed the plastic bags from Baggy's reach, could it be he has
hairballs?

My now six-year-old cat was throwing up last year and refused to use his litter
box for urinating. (He'd use the shower stall instead.) I switched to canned
food for awhile and he did a little better. Then I started giving him a one-inch
ribbon of (petroleum-jelly based) hairball remedy each day for a couple of
weeks. Also, I switched from regular Iams to "hairball remedy" Iams. It has more
fiber. (Others here at the time suggested more fiber and mentioned several
things I could feed him.) He ultimately made it to a one-inch ribbon a couple of
times a week. Now he has the hairball remedy a few times a month.

He's fine now. He rarely vomits and has good litter box habits. I give him
mostly the Iams hairball formula but also a couple of lumps of canned whitefish
(cat food version) each day.

One can buy the hairball remedy at Wal-Mart or most any pet store. Hartz has a
version. Four dollars or so a tube that lasts a long time.

Updates welcome. :-)

Vomiting can be a symptom of an underlying disease (ie. inflammatory bowel
disease, etc). He should be checked by a vet to rule these out.
Gail