Lower esophageal sphincter acts as a valve between the esophagus and stomach. When a child swallows, this muscle lets food pass from the esophagus and stomach. This muscle stays closed normally and the stomach content doesn’t flow back into the esophagus.
In children having reflux and GERD, this muscle becomes weak and relaxes when it should not and the stomach contents flow back into the esophagus. This happens because of,
- Hiatal hernia, a condition where the upper part of the stomach pushes upward into the chest through the opening in the diaphragm
- Increased pressure in the abdomen from being overweight or obesity
- Medicines such as asthma medicines, antihistamines, pain relievers, sedatives, and antidepressants
- Smoking or exposure to secondhand smoke
- Previous surgery on the esophagus or upper abdomen
- Severe developmental delay
- Certain neurological conditions such as cerebral palsy