Anal bleeding or hemerroids?

[Sassywassy455]

So recently I’ve had a little dark blood/ mucus coming from my anal area, it was very minimal and only happened when wiping (not enough to see in toilet) and even then, only happened once every few months, and always right after a bowel movement. I still went to the doctor, he did a digital exam and concluded I don’t have any hemerrhoids or fissures. He said given my age (I’m only 20) I probably don’t have anything serious and it was most likely something I ate and that I need to calm down. I didn’t like this answer, so I went to a different doctor. I’ve had a nurse recommend a colonoscopy for me, but this new doctor said that’s not needed, and it would be needed if I had more serious symptoms or was in pain, which I’m not. I did have some intestinal pain and diarrhea and alternating constipation, but it went away when I cut out dairy and gluten from my diet.

So my main question is, is it possible there could be a fissure or hemerroid that’s too deep in my colon for the doctor to notice during a digital exam? Or could this bleeding have been related to my intestinal issues that went away when I cut out dairy and gluten from my diet?