I had been suffering similar things and was way too embarrassed to say anything. Then a few months ago starting to experience the most horrific stomach pains where I could not lie or stand straight. DH took me to emergency ad they found that my intestine was inside my stomach and I needed emergency surgery there and then to remove it.
Now.. The surgeon hasn't seen anything like it before and I was in hospital for 5 days - I'm not saying that this is what you are experiencing.... But I now believe it when blood should not be coming out of your bum (I never listen to my body). Go to the dr and get some piece of mind or some treatment before it gets real bad.
Yep really embarrassing, but quite common symptom for many things!