What condition is characterized by a malfunctioning lower esophageal sphincter that allows gastric juices to rise into the esophagus?

Gastroesophageal reflux disease (GERD) is characterized by the malfunction of the lower esophageal sphincter, a muscular ring that serves as a barrier between the stomach and the esophagus. When this sphincter is weakened or relaxed inappropriately, gastric juices, which contain hydrochloric acid and digestive enzymes, can flow back into the esophagus. This backflow, or reflux, can cause symptoms such as heartburn, regurgitation, and discomfort in the chest and throat.

The hallmark of GERD is not only the presence of acid reflux but also its chronic nature, which can lead to complications if left untreated. These complications may include esophagitis, Barrett’s esophagus, or even esophageal cancer over time. The condition often requires lifestyle changes, medication, or in some cases, surgical intervention to manage the reflux and protect the esophagus from damage.

In comparison, the other conditions mentioned do not typically involve the malfunction of the lower esophageal sphincter as a primary feature. Appendicitis is an inflammation of the appendix, lactose intolerance is the inability to properly digest lactose found in dairy products, and Crohn's disease is an inflammatory bowel disease affecting the gastrointestinal tract. None of these conditions directly relate to