Can gas cause upper right stomach tenderness? and loss of appetite , i have been told in the past that i have gas problems?

Excess gas production in either the stomach or intestines can be due to a gut flora imbalance. Normal gut bacteria are diminished, and gas producing bacteria can be over produced depending on antibiotic use, diet (too much sugar), lack of fiber. There can also be many other causes of upper right stomach tenderness. Evaluation by the same Dr that has followed you for this in the past can help.