It is possible to get bowel cancer at the age of 18, but the chances of bowel cancer occurring at this age are rare, and bowel cancer usually occurs after the age of 40. If you get bowel cancer at the age of 18, the malignancy of bowel cancer is often very high, and it is especially prone to distant metastasis. Even if it is resected through surgery, the chances of recurrence and metastasis in the future are higher than that of middle-aged and old people, so you need to have adjuvant chemotherapy after the surgery as well. Apart from bowel cancer, 18-year-olds have a higher chance of getting benign bowel diseases, such as ulcerative colitis, Crohn’s disease and intestinal tuberculosis, which can be detected by electronic colonoscopy. Different benign bowel diseases are treated differently.