Alternating bowel movements of green stools with some black dots of constipation ad diarrhea, bloated, small poop comes outs18 years old colon cancer?

Diet. The appearance of feces varies according to diet, your level of hydration, your gut's microbial flora, medications, and your bodies own makeup. Colin cancer is rare in an 18 year old. It may cause blood to appear in the stool but often just small amounts that is not visible, and requires a chemical test. Cancer does not typically cause diarrhea except for a rare form called villous adenoma. .