I agree, I would make an appt. to see a Gastroenterologist because this is who your GP is going to refer you to anyway. It's their specialty and they get right to the problem quickly. If you didn't have a colonoscopy at 50, it's time for that anyway and a GI doctor is who will do that. Don't get upset, there are many minor things that can cause this, and getting checked out can get you back to normal. I wish you all the best!
Welcome to the gastroenterology community! I would recommend seeing your doctor about this and getting some testing done.