I took a combination of tylenol and codeine for a sore back Sunday night. Monday I had a light colored stool - grayish, tan color. I continued the codeine/tylenol Monday and Tuesday night. I am still having light colored stools. I also take Keppra but have been on it for about 5-6 years. When I checked on the internet, it said this could be due to colon cancer, pancreatic cancer or gall bladder/liver issues. I am not jaundiced. How soon would that appear? What type of doctor should I go see. I am 55. My only colonoscopy was 10 years ago. Thank you.