I can totally identify with the outside pain trigger. Mine is on the left side - an ovary encased in adhesions.. pants are my worst enemy!! I no longer wear pants that cut across my waistline unless I have to.
I wear overalls nearly everyday and have for the last three years. (I own 10 sets) I am female, 135 lbs. - so I buy mens cut (the female versions are too tight for my comfort level), med - lg (not too baggy - but never cutting me at the waist)
This particular type of clothing has been a godsend. Maybe this can help you too -
Carli