Blood In Stool More Condition/symptoms What Could Be The Cause Of Blood In Stool?

What could be the cause of blood in stool? - blood in stool more condition/symptoms

My Boston Terrier puppy (almost five months) has blood in the stool. She has loose stools are normal, which tell us that he needed, had to purchase food, the results have been accustomed to. It is carefully so it took a while until we understand what is eaten. She is happy, very energetic, weight gain. She woke out twice last night (very rare, because they can not sleep all night) and when I took her intestines were softer than usual, but it seemed normal, and when my husband had lasted two hours later, mucusy. As he wiped the blood, which was in brilliant color in the fabric.
We take the vet today. Any idea about the cause? He is constantly being reviewed, but I wonder if I am something like a stone or a stone, it may have eaten it.