Very often one of my cats goes to the bathroom, but when she goes #2 it's usually very loose or often diarrhea. She has a habit of when she goes that blood and what looks like mucus come out too, often sticking to the back of her tail and rear. she frequently scoots along the floor to get it off. This has been happening for more than 2 years, and each time we go to our vet we tell them this and all they do is express her anal glands. It's a temporary solution, but no more than 1-2 weeks later she's back to doing this again. We've had her tested for internal parasites each year, and it always comes back negative. I dont know what this could be but i'm sure it's not normal. Here are some pics, mabye you can help me figure this out?