Unexpectedly we lost 1 of our cats (indoors only and neutered). Marbles was not 2 yet and seemed to have good health and always had tons of energy. A month ago he had a urinary tract infection but we got that cleared up. A week ago he started yowling horribly and then threw-up ,then yowled horribly in the litter box and had some mucous diarrhea. We took him to the emergency vet and they did blood work on him. All the test showed was that he was dehydrated. Everything else looked fine except for an elevated glucose level. They kept him over night and for the next two days he went back and forth from day vet to night vet. He kept only having mucous,no smell bowl movements and not eating.They did tons of x-rays and from all they could tell, there seemed to be an obstruction in his intestines. We kept getting told it would be fine. Finally on Friday at 1 am they opened him to remove the "obstruction" only to find his colon was 90% dead and no obstruction. He had to be put to sleep. We did not get to say good-bye and thought he would be fine and recover. His sister, Snickers, is mourning. She is now not really eating. She has been throwing up as well and we are freaked that she is now having the same problem. We don't know what to do. We miss Marbles SO much and don't want to lose another cat. Any info. that anyone has would be a huge help! Thank you in advance.