I think I have a problem with going to the toilet, please read and answer?

So I don't know how to exactly describe my problem, and I go the toilet enough. My problem is that I always stick my fingers up my backside to do a number two. I feel like I can't do a number two unless I do this. I'm not sure why I do this, but I think it started when I was constipated once and couldn't get the 'poo' out. Now I do it all the time even when there's no need. Why do I do this? Is it just a habit? I'm quite confused, and it's gross.