When we put all of his symptoms together I am a bit concerned about a piece of plastic obstructed in his gastrointestinal tract. Unfortunately, on history only it will not be possible to determine if the plastic is obstructed or not, I am sorry. I would strongly recommend having him checked by your family veterinarian for x-rays with barium. I realize that this answer may not be entirely to your liking, and I regret being the bearer of information that you really don’t want to hear. But it would be unfair to you and unprofessional of me were I to provide you with anything less than truthful and honest information. I hope you understand. In the meantime, this is what you can do:
1- Do not give things like Pepto Bismol or Imodium. Start him on Pepcid AC (famotidine) 10mg tablet every 12 hours for the next 2-3 days. You can buy Pepcid AC over the counter in any pharmacy.
2- No food or water for 6-8 hours. Need to give his gastrointestinal tract time to rest.
3- After 6-8 hours offer a small amount of water. Wait half hour, if no vomiting, offer a small amount of rice (50%) and boiled boneless chicken or ground beef (50%) 4-6 times a day. Keep on this diet for several days then wean into regular diet.
4- Follow up with your family veterinarian for a hands on examination. If cost is a concerned I would look into your local ASPCA or Shelter where they often offer veterinary services at a lower cost.
My goal is to provide you with excellent service - I hope I've provided the information you were seeking, if you feel you have received anything less, please reply back as I am happy to address follow-up questions. Kindly rate me when you are done.