Help please

My cat was fine in the morning. Then randomly he started to foam at the mouth and we took him to urgent care. They took his blood and said everything is fine blood wise but the x ray has some worry’s. Something about his small intestines. they gave him some medicine and ever since we got home he has been drooling slightly and hiding away. The vet said you wouldn’t see any changes until tomorrow but i can’t help myself from worrying. He’s 9-10 years old. no organ failure or anything. I’m scared