Would colon cancer cause the ln in the mesentery to swell up and cause notable pain/swelling on touch?

Unlikely: Colon cancer does spread to the local lymph nodes but generally there are no symptoms from that. Unless you have family history of early age colon cancer, you need not worry about colon cancer at your age. For good health - Have a diet rich in fresh vegetables, fruits, whole grains, low fat milk and milk products, nuts, beans, legumes, lentils and small amounts of lean meats. Avoid saturated fats. 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.