WOW, im dealing with the exact same thing you are. Hiatal hernia, and the pains right on top of the ribe cage. It feels like it in between the ribs. Also loose stools with alot of undigested food. I suspect leaky gut causing this.
Anyway, yes right now im taking L-glutamine powder. It is helping alot. for the stomach issues and food in the stolls. If now i could only get rid of my other full body muscle symptoms.