Malteses

I have a 1yr and a half male maltese, he has been (sorry to be so descriptive but..) going poo with blood stains on his wee pad and poo with mucus. i am very worrried, my vet told me to come in , in 2 days but i am very worried since he has been going poo for about 48 hrs and its been looking like that. I am worried since a day before this happend i left him with my cousins yorkie and when i came back i found him inth eback yard. theres no way for him to have gotten there unless he jumped out the window which is like 6.5ft off the ground . He seemed fine but now this is all gettingme worried and the vet still is in 2 days i wonder if this is a serious matter. I hoe someone out there can help me please