The past couple times I have defecated I've noticed small amounts of blood when I first wipe. No more appears after the first wipe.

I'm guessing this means there is a slight tear in the anus that gets agitated as the stool passes.

Nothing has gone up there thats not supposed to, so I'm not sure why there would be a cut. I'm a college student so my diet isn't exactly balanced. I'm not sure what dietary deficiency would account for thin anal skin.