"Hiatal hernia just about always accompanies a swollen ileocecal valve. The ileocecal valve is the valve between the small and large intestines which permits material to enter the colon from the large intestine, but prevents material in the colon from moving back into the small intestine. When this valve becomes swollen and irritated it cannot close properly. This allows material from the colon to leak back into the small intestine. This is analogous your sewer backing up into your kitchen. This creates gas and indigestion, which puts pressure on the stomach and presses it tighter against the diaphragm. "