I had a cat who got REALLY sick as a kitten... just stopped eating and got super skinny. So we took him to the vet and the vet gave him steroids which only helped for a few days. About a week later we took him back and told the vet "help him or put him down". I mean he was skin and bones and totally lethargic.
So the vet tells us "the only thing left we can do is 'exploratory surgery'... open him up and look around."
So we say fuck it, have at him. They open the cat up and inside they find an almond that he had swallowed and had completely blocked off his intestines.
$2,000 later he's all better and eating again.
That cat, no bullshit, hit 32lbs before he died about 7 years later.