GASTROESOPHAGEAL REFLUX DISEASE (GERD)

DEFINITION
Symptoms or mucosal damage produced by the abnormal reflux of gastric contents into the esophagus is known as gastro esophageal reflux disease [1]
Nonerosive gastro esophageal reflux disease
The majority of patients with typical symptoms of GERD do not have esophagitis; such patients have been referred to as having nonerosive reflux disease (NERD) [10]
DIAGNOSTIC CRITERIA

• The cardinal symptoms associated with GERD are heartburn and regurgitation. However, complications from GERD can arise even in patients who lack these typical symptoms [1].
• Heartburn may be exacerbated by meals, bending, or recumbency.
• Typical uncomplicated cases do not require diagnostic studies.
• Endoscopy demonstrates abnormalities in < 50% of patients [1].
• Barium esophagography is seldom helpful.

EPIDEMIOLOGY
An approximate prevalence of 10 to 20 percent is identified for GERD (as defined by at least weekly heartburn and/or acid regurgitation) in the Western world while the prevalence is lower (5 percent) in Asia. The incidence in the Western world was approximately 5 per 1000 person years [2, 3]. One study from Singapore [5] reported very low prevalence in the region at 2% while another from China reported the prevalence at 6% [4], but there is now evidence to suggest that its frequency is rapidly rising in Asia [6].
Race
• White males are at a greater risk for Barrett esophagus and adenocarcinoma than other populations.
Sex
• No sexual predilection exists. GERD is as common in men as in women [2].
• The male-to-female ratio for esophagitis is 2:1-3:1. The male-to-female ratio for Barrett esophagus is 10:1.
Age
• GERD occurs in all age groups [2].
• The prevalence of GERD increases in people older than 40 years [2].

Causal Mechanisms of GER [7]
o Transient relaxation of the lower esophageal sphincter
o Increased intra-abdominal pressure that overpowers a decrease in lower esophageal sphincter tone
o Impaired esophageal or gastric motility
o Certain medical conditions like scleroderma are associated with diminished peristalsis. Sjogren's syndrome, anticholinergic medications and oral radiation therapy may exacerbate GERD due to impaired salivation
o If hiatal hernia is present which is usually silent may be associated with higher amounts of acid reflux and delayed esophageal clearenceleading to more severe esophigitis especially Barret's esophagus