Cat is vomiting daily

Question
I just adopted two cats from my local shelter a week ago.  They are 8 years old.  The male is a domestic short hair cat with a vomiting problem.  On a daily basic he is vomiting- I took him to the vet last week and he found nothing wrong but the problem has continued.  I called the shelter and they said he never had a problem while in the shelter and other than that he is fairly healthy.  He loves his new home and other than throwing up everyday he seems fine.  Do you think its the food?  Both him and his sister get regular dry purina cat chow. What do you feed your cats?  I don't think its a hairball problem because I am not seeing any hair.  So what do you think could be the problem?  I am getting tired of cleaning the carpet.  Another question do you know of any good cleaner to get vomit out of the carpet?  Thanks in advance!

Answer
you might need to use a dry cat food for sensitive tummy. i think purina makes one. i know you can buy it at petsmart. also ask the vet for some catlax. cat laxative is not like human laxative, cat lax aids in digestion and sooths the belly, try giving it to him daily for a week, then every other day for a week, then every 3 days a week, then once a week, then only when he needs it.

ok ..now about getting the vomit out of the carpet. i know it sounds terrible, but if you leave it there till it is dried up, it peels right off the carpet and leaves less of a stain. buy a carpet cleaner liquid for carpet cleaner machines(you do not need to buy the machine, just the cleaner),that says its for pet stains and odors, follow the mixing instructions for it, but put it in a spray bottle, after you peel the vomit up, spray the area and use a scrub brush to work the cleaner into the fibers, then use a fluffy towel to absorb it all up out of the carpet.i just fold the towel up on it and stand on the towel

i use the same towel for this, i just hand wash it after im done and hang it to dry so its ready for the next time.