One Year Ago I Had A Colonoscopy For Severe Abdominal

One year ago I had a colonoscopy for severe abdominal pain and blood in my stool. The blood is bright red and ringed around the poop and only appears on the first wipe. The colonoscopy showed no signs of polyps or cancer. The doctor said there was a possibility of small internal hemorrhoids. A few days after the procedure I had abdominal pain so painful I was toppled over for most of the day. Over the past year I've had occasional bleeding and constant stomach pains. The past month the bleeding has come back. Every so many days I notice the bleeding. One morning I was cramping and having the pains again and passed a bowel movement with a lot of blood. My GP is referring me to a gastroenterologist again. Is there a possibility this could be something other than hemorrhoids ? Could something have been missed in the colonoscopy a year ago ? Also, when I wipe after I poop, there is almost always thin clear mucus on the toilet paper and no trace of the poop. Only the thin mucus. Thank you for your help.