I am 19 years old. Will be 20 in January. I know it is rare at my age, especially with no family history, but i have been concerned about rectal cancer. A few months ago, i woke up one morning to diarrhea. It had a small red slimy, or mucousy looking blood blob in it. Did not mix in with the water or turn the water red, it was just a small blob that floated on top the water. Hadnt had anymore diarrhea or blood after that and went to the doctor and he said it was common to see blood with diarrhea sometimes, long as it doesnt continue. Then a week later i had this strange fullness sensation in my rectum, felt like my rectum was tight or something and it was very hard to pass stools. Doctor have me hydrocortisone cream thinking it might be internal hemmorhoids, and by the second day the pain went away. Well, its not internal hemmorhoids. I dont feel any, and every couple months the pain comes back. Recently it started again but now i am having thin stools followed by sometimes watery diarrhea with unformed stools, but today i had complete liquidy diarrhea that turned the toilet water green, follow by very thin green stools. I am concerned. The stools kind of alternate, going from almost normal then back to thin. But lately ive had bouts of diarrhea. The only people in my family that had it was my grandmothers sister, colon cancer, and my grandmothers brother, polyps. Both of average age for the accurence. Neither my parents or my grandparents had this problem.