We adopted a 5- 6 month old cat yesterday and brought him home about 5pm. We set him up in our spare bedroom with toys, litterbox and plenty of food/water. Our resident cat has hissed twice and growled. Last night before I went to bed, our resident cat had LIQUID diarrhea. I thought he was peeing from the way it sounded until I went and looked and it had no form whatsoever. Is this just from the stress of the new cat? Im worried that this isnt going to work out and I dont want our resident cat getting sick! He already had diarrhea issues in the past and gets a probiotic daily. Can anyone suggest anything else I could do? Thanks!