Thank you for using justanswer. I am sorry that Archie is having problems. blood from the anus can be a result of several problems including colitis, constipation, parasites, or an anal gland abscess.
Since Archie is acting fine right now, I think it is ok for you to monitor him until tomorrow when your regular veterinarian is open and can see him. If Archie begins vomiting, becomes lethargic or begins straining to go to the bathroom without being able to produce anything however, I would take him in to the emergency vet today.
Best wishes to Archie for a speedy recovery!
He was straining a little earlier today but did get out a couple small pieces of hard stool. This is the first time I have seen him do that and he went on playing and acting normal and ate like if nothing. Is this normal behavior if he was in pain?
I would not expect him to be acting so normal if he was in pain. The hard stools that he passed earlier may indicate that he has a little constipation and that would explain the straining and bit of blood that you are seeing. I would monitor his subsequent stools and if they remain small and hard, your veterinarian may find that an enema is necessary to help him pass the remainder of the hard stools. However, it sounds like he is comfortable and stable for right now.