Chronic condition in which retrograde flow of stomach contents into the esophagus causes irritation to the epithelial lining.

Prevalence: ∼15–30% in the US (increases with age)

Risk factors/associations:- Lifestyle habits such as smoking and alcohol consumption- Increased intraabdominal pressure: Obesity, pregnancy, ileus, diaphragm dysfunction- Angle of His enlargement (> 60°)- Gastrointestinal malformations and tumors: gastric outlet obstruction, gastric cardiac carcinoma- Scleroderma- Sliding hiatal hernia- Medications: Atropin, calcium antagonists

Clinical features:- Retrosternal burning pain (heartburn) that worsens while lying down (e.g., at night) and after eating- Regurgitation- Dysphagia- Chronic non-productive cough - Nausea and vomiting- Halitosis

Diagnosis:- If GERD is clinically suspected → Empirical therapy- Upper endoscopy- Esophageal pH monitoring- Esophageal manometry

Pathology:- Superficial coagulative necrosis in the non-keratinized squamous epithelium- Thickening of the basal cell layer- Elongation of the papillae in the lamina propria and dilation of the vascular channels at the tip of the papillae (→ hyperemia)- Inflammatory cells (granulocytes, lymphocytes, macrophages)- Transformation of squamous into columnar epithelium → Barrett's metaplasia

Treatment:- Lifestyle modifications: Small portions, avoid eating before bedtime, normalize body weight, smoking/alcohol/drug cessation- Treatment of choice: Standard-dose of PPI for at least 8 weeks (once daily therapy)- Fundoplication