This study aims to learn more about the effects of naproxen and aspirin on the normal colon in people with Lynch syndrome. By doing this study, the study team hopes to gather information on the safety and effectiveness of naproxen and/or aspirin for the use of cancer immune interception in Lynch syndrome. Naproxen or aspirin may help to prevent the development of cancerous cells in the colon.   
  
Naproxen and aspirin are both approved by the U.S. Food and Drug Administration (FDA) to relieve pain and fever, however it is considered investigational to give naproxen or aspirin to patients with Lynch syndrome.

Participants will be randomly assigned to receive either naproxen or aspirin. Randomization is like flipping a coin and there is a 50/50 chance of being assigned to either group.

Participants will take either naproxen or aspirin capsules by mouth 1 time each day. There will also be study visits and study calls throughout the duration of the study.   

Total study participation will last about one year.