Muscle Pain In Right Side Abdominal.

I have mild muscle pain in right side abdominal past 10 months  24*7 when I am noticed my abdomin I feel mild pain this is irritating me. i am able to find the reason. I am seen the general doctor he prescribed omiprozole, pantaprozole, rabezole table and muscle relax tablets But pain  is not solved. after I went to gastrologyst he suggested Blood test and ultrasound, cbc, hb,sugar, urea, serum, all normal vitamin D level only below normal and untrasound report also normal he prescribed vitamin D, deltoneprozole, estimoprozole, multivitamin, muscle relax tablets and b complex injection but the pain not resolved. what is the reason for this pain.  I will take this pain normal or some infection in my body or nerves problem or stress pain or gastric or other problem in my body the pain is alarm for that I don't know. I am also tried walking and gym also but the pain is solve.  please help and suggest what is the reason doctor?