Can a patient with internal hemorrhoids and heavy bleeding have cancer?

Hello doctor,

I am a 37-year-old male, and I have had blood in my stools for about three days every two weeks for the last eight months. I went to a doctor who did a digital rectal exam and anoscopy. I was diagnosed with hemorrhoids. He prescribed some cream, which I used often. However, the bleeding continued, and then I got anxious. So, I went to the other doctor, who suggested a colonoscopy. I underwent colonoscopy a couple of weeks ago, and everything was clear, except grade 1 hemorrhoids and mild diverticulosis, but the doctor said it is common. No polyps or inflammation was seen. No biopsies were taken. The doctor said my next colonoscopy would be done after 13 years. This week, I saw blood on the toilet paper and a few drops on the stools. I have regular bowel movements with soft stools. I have no pain, except when I go to the toilet. How can grade 1 internal hemorrhoids cause bleeding so frequently? Is there anyone else with internal hemorrhoids and heavy bleeding? Is it something serious? Did colonoscopy fail to detect cancer?