My kitten is 4 month old and he is always so playful, let's you hold him, very adventurous and loving. But today when I got home he was making a really loud scream and hissing. He would also just poop all over the place. His tail was straight up with his fur sticking up as well. He was really scared. At first I didn't know what but then my other cat (his mother) came near him and started to freak out again with the screams and hissing. He will lets hold him and he seems to be extremely attached to me and will cry every time I leave him. I just would like some ideas of what could possibly wrong. I have googled everything and can't seem to figure out anything, please help me if you know what could be wrong