Constant heaviness on right side from kidney to appendix.

Hello and welcome to e health forum.

The description of your symptoms indicate the possibility of enteritis, or colitis (Inflammation of the small or large intestines). Other causes of right upper back pain can be renal stones or renal infections).

For a proper diagnosis, you may need a few investigations including a urinalysis, a Ultrasound or CT of the abdomen.

You may consult with your doctor, who can do the needful for you.