Stomach and abdominal pain with rectal bleeding (dark + light ) but not crohns. also have been eating super healthy and working out to lose weight.?

Concerning: Rectal bleeding is always a concern, and could represent many different diseases including cancer, although at 19 years that is very unlikely. However you could have gastritis, ulcerative colitis or several other conditions. It may be as simple as hemorrhoids, although that is usually bright red blood. See a doctor - it has to be evaluated.