Hi Jen. Sorry to hear about this. My Cleo had very loose stools two or three years ago and my vet suggested I try her on Hills Veterinary Diet, Feline w/d to bulk up her faeces. This has worked well for her. Just a little each day at both meals with her wet food. One time when all the vets were out of stock and we were waiting for a new shipment to arrive, I had run out and after a week or two her stools became runny again. As soon as I recommenced the Feline w/d all was well once more. Ask your vet what s/he thinks and maybe give it a try. Cleo is now 16 by the way, how old is Lucas?