The MS hug commonly appears in the trunk area of the body (stomach, chest, sides and back) Feels like you are being squeezed, like wearing something too tight. Breathing is difficult sometimes too especially if it occurs in the chest area.
I'm sorry you are having the stabbing pains in your stomach
My hubby does get the hug but never has had that kind of problem. Hope it gets better and they figure out what's causing it.