anal pain and large open sore

Hello all, I had a fissure several years ago, and it healed up nicely with sitz baths and high-fiber diet. So I know what a fissure can feel like. What I have now doesn't feel like a fissure. It feels like a splotchy-shaped open sore on the inside of my anus. It has been there for years. The last time my doc checked it, at my insistence, she said that she couldn't feel anything. I assume she thought that she was looking for a fissure.

This sore itches terribly, especially when I eat high-residue foods like nuts and small pieces get stuck there. Or when I walk or exercise and sweat more. I use a lot of OTC lidocaine ointment to keep it from driving me crazy.

Should I be insisting on seeing a GI specialist about this sore? My big question is whether it could actually be a fissure, just shaped oddly.

Thanks.