Yesterday afternoon Cooper was laying down sleeping most of the day (which is what he does on Sundays) and he got up and started sniffing around like he had to go to the bathroom so I jumped up and let him out. Pretty much as soon as I let him out of the house he had diarreah. I didn't think anything of it, just thought maybe he wasn't feeling well. Then last night I let him out around 9 and could tell he had to go because he kept straining, but nothing was coming out but gas. After a while, I just let him in again. I let him out one last time at 11 and went out with him and the same thing happened. He kept straining but nothing was really coming out. He had a little diarreah again but then kept going to different spots and trying to go but nothing came out. When we went inside he was acting strange- wouldn't leave my side by more than like 6 inches. And he kept sitting and scooting his butt a little every few steps he would take. I brought him upstairs and put him in his crate for the night and was woken up at 4 am because he threw up food in his crate. It must have been his dinner, it was all just food chunks, nothing else came up with hit. Then I remembered that he threw up food chunks yesterday morning too, but I just thought it was because he ate breakfast and then ran around the house like a nut job. I let him in the yard again at 4 this morning and he had a little diarreah again but seemed like he still had to go and couldn't. I'm worried that he might have some sort of blockage but didn't know if he would still have diarreah if he did. Should I switch him to chicken and rice and just watch him closely, or do you think I should rush him in to the vet today?