What are the chances of a 30-year-old male having colorectal cancer? exactly how many cases of colorectal cancer are diagnosed in this age group?

Unlikely: With knowing just your age, rest assured, it's very unlikely. Generally speaking, colorectal cancers are one of the cancers where routine screening is known to improve survival rates. The recommended screening schedule depends on your risk level and is outlined nicely here: http://bit.ly/2nexSdl If you are still pretty worried, a longer talk with your Doctor may help. Try not to stress too much

Family history: Is there a family history of colon cancer occurring at an early age? If no, your risk is negligible. If there is family history of early age colon cancer, get a colonoscopy at the 10 years before the earliest age at which colon cancer occurred in the family. The rate of colon cancer in 30 year-olds is general population is not relevant to a given individual. For good health - Have a diet rich in fresh vegetables, fruits, whole grains, milk and milk products, nuts, beans, legumes, lentils and small amounts of lean meats. Avoid saturated fats. Drink enough water daily, so that your urine is mostly colorless. Exercise at least 150 minutes/week and increase the intensity of exercise gradually. Do not use tobacco, alcohol, weed or street drugs in any form. Practice safe sex, if you have sex.