Re: unknown tummy problems
You said endoscopy, but not colonoscopy? Sounds like you need one!
I'd push getting diagnosed especially with the blood, that sounds dangerous. I've had some of that bright red blood too but not as bad as if sounds you have. Not sure how it works in the UK, but I finally switched doctors and I'm finally getting answers.
I think if you have that much blood maybe you should to to the urgent care until they help you. There is obviously something wrong.
Good luck, get pushy!