Please help

[babygurl290]

So I started having blood in my stool back in August when I noticed a drop in my Hemoglobin. I took a stool test which came back positive for blood, so my GI recommended a colonoscopy and endoscopy. Both tests came back clean, so I left it at that. However, I was still feeling run down and was having increased bowel movements. I took another blood test which showed I was anemic, and my new GI ordered another stool test, which came back positive again. Because of this, I got another colonoscopy in case the first one missed something, as well as an MR Enterography to check the small intestine. Both tests came back normal.

My question is, what could possibly be causing the bleeding if all the tests I've taken so far have come back normal? The GI who ordered the colonoscopy and MRE is my third GI, and at this point my parents are tired of doing all this testing. I just don't know what to do because I'm having this problem yet we can't even figure out what's causing it. This whole thing is making me really worried and is really affecting my state of mind as well. Any help would be appreciated.

I'm also a 17 year old female, if that helps at all.

[Danny90]

Are you constipated?