Final answer:
A finding specific to hiatal hernia is a weakened lower esophageal sphincter, which allows stomach acid to flow back into the esophagus.
Step-by-step explanation:
A finding specific to hiatal hernia is a weakened lower esophageal sphincter. Hiatal hernia occurs when the upper part of the stomach protrudes through the diaphragm into the chest cavity, leading to symptoms such as heartburn, regurgitation, and chest pain. The weakened lower esophageal sphincter allows stomach acid to flow back into the esophagus, causing these symptoms.