Cats

So my cat was kicked by someone and I took him to the vet, they said that he had 2 broken ribs and his body wall was broken too, he went into surgery and recovered. But I went travelling for a month and I come back to find that there was something that poking out (from the inside but not through skin) . He doesn’t seem to be in any pain and can do all things normally but I really don’t know what to do. Some advice will be greatly appreciated :)