What Causes Bleeding From Anus After Using An Enema?

I used an enema and when I removed it there was blood that had traveled back inside of the tube and mixed in with the remaining solution. It was bright and red. Also, I sometimes pass blood in my stools. Sometimes it s a little sometimes it s a lot... Very scary and sometimes my anus hurts on one side for minutes at a time. I have digestive problems for years and did see a doctor but noting serious came back. I do think I have an internal hemrroid that may bleed... I need help on what to do.