If the anus was scraped the inside blood wouldn't be mucous like. If the anus is scraped the water would be pink from the blood. If the objects in the water are mucousy blood colored then that means the blood came from the inside. I've seen many, many GI bleeds ( 7 years) and once you get used to seeing them you can pretty much know whether the bleeding is inside or not. Now if the bleeding gets worse a person will see it everytime they move their bowels and you will know epecially because the smell is worse than fecal smells. (I try to encourage the patients and let them know many patients come to the hospital with this problem and that the docs get to the bottom and find out what causes the bleedings, because they all are embarassed and afraid) I wanted to mention that (excessive cleansing could cause some internal bleeding) but I didn't want to scare anyone in this forum. Even when someone is Anorexic, if they continue vomiting over periods of time eventually they start bleeding inside. Maybe you should put some lubercant on the nozzle tip (of the enema) to prevent this from happening again.