You are being treated for heartburn or hiatal hernia, and you feel sudden chest or stomach pain, have difficulty swallowing, are vomiting, or are unable to have a bowel movement or pass gas; you may have a hernia that has become obstructed or strangulated, which are emergencies.
One strong possibility for your symptom is gall bladder stones and cholesterol deposits within the gall bladder which can cause sharp pain. Getting an ultrasound of the upper abdomen done in a walk in clinic or the ER will confirm the diagnosis.
When I bend a certain way I feel like my stomach or intestine on the left side of my upper abdomen is twisting into a knot. The pain is horrible. It's like a leg cramp. I can actually see it through my skin. I have to stand up and stretch out my torso to make it go away.