Is frequent yellow solid stool and orange diarrhea with cramping nausea and losing 106 lb in 1.5 years a cause for concern?

Yes. Yes. It's concerning, and should be evaluated by a physician in person. It would be best to schedule a visit with your doctor (and board certified physician in Family Medicine or Internal Medicine is your best starting point) as soon as possible. In the meantime I suggest keeping a food and beverage diary along with writing down when you use the restroom and describing your experiences. .