Hiatal hernia is a structurally correctable digestion problem that is common in the general population.
With a hiatal hernia, the problem starts with improperly inhibited muscles between the ribs and the pelvis. A major muscle or muscle group that attaches to the ribs is weak. This is usually because of back injury or strain on the abdominal muscles, like in pregnancy. The left shoulder is often involved.
The weakness allows the ribcage to elevate on one side, causing a gap in the diaphragm that allows the stomach to be pulled up into the chest cavity. The “hernia” of a hiatal hernia is not usually a tearing or a rip like other hernias (inguinal or abdominal.) The diaphragm is not a solid layer of muscles, it’s overlapping segments that can gap if the ribcage is not properly aligned.

In the diagram at left the esophagus is represented in green, the stomach in red and the diaphragm is represented in purple.
A is the normal anatomy
B is a pre-stage
C is a sliding hiatal hernia
D is a paraesophageal type.
Chiropractors practicing Sacral Occipital Technique (a popular chiropractic technique, which I use some of in my practice) have conducted a study and presented their findings on treating GERD with chiropractic adjusting, here is a link to their study.
Abdominal and digestive issues
Other abdominal issues that respond to applied kinesiology techniques and manual manipulation include iliocecal valve dysfunction and pyloric valve dysfunction. Dysbiosis, including excessive gas and bloating caused by improper gut biochemistry and/or microbial imbalance, can be effectively addressed with vial test kits to determine reactivity to the environment, diet, and biological processes.