My 5 month douge de bordeaux has eat a plastic food bag about 3 days ago, and nothing has came up, my mum doesn't think he's being himself lately, neither do I. were not sure weather to take him the vet or not. He's vomited like once or something, and he's poo'd but nothing has came out. Please help me and tell me what I can do? I don't want him to die, he's my baby :(

A vet visit is in order.