Problems With Stools.

For the past few months I've been having some problems when I go for a bowel movement. I've been having bloody stools, sometimes with pain, sometimes its attached, or sometimes it's just on the toilet paper or in the toilet itself. I have pains in my stomach but very rarely, I went to the doctors and he did a VERY quick exam and thinks it may be hemroids, and prescribed me some medication to see if that would fix the problem. However, I am only 16 years old and this is a problem seen in middle aged people, so I'm wondering if it could be something different because he did not really know the details, and if I should go for further testing if the medication doesn't work, thanks.