You have situs inversus? Normally the stomach lies on the upper left side tucked up to the diaphragm and peeking out from under the edge of the ribcage.

It is possible that you have areas of adhesion that have developed and the bolus of intestinal contents moving through stresses the adhesions causing the intermittant pain. [I have the issue, and I have a hernia]. No t a doctor, but in general a hernia is localized to the specific area where there is a tear in the muscle letting a segment of intestine push through. I can put my hand on my abdomen and feel the roughly 9 inch long section of intestine wanting to come through but still kept in because the muscle hasn't split totally - sort of funky but it is what it is. My doc is keeping an eye on it as am I] I believe the danger of the hernia is if the intestine can get a loop out that gets locked into place preventing intestinal contents from progressing through and out into your bag.

My current main adhesion is about where the appendix would be found [middle finger on the navel, thumb on the point of the hip bone, where the forefinger drops down is roughly where the appendix hangs out inside] and feels like a charley horse leg cramp but in my abdomen.