Gastroesophageal Reflux Disease (GERD) Overview

Gastroesophageal Reflux Disease (GERD)

• Definition: Most common cause of esophagitis due to reflux of gastric or duodenal contents into the lower esophagus. Esophageal squamous epithelium is vulnerable to acid damage.
• Etiology: Decreased efficiency of esophageal antireflux mechanisms (especially lower esophageal tone), increased risk with alcohol and other central nervous system depressants, delayed gastric emptying, hypothyroidism, pregnancy, sliding hiatal hernia, and tobacco use.
• Clinical Features: Symptoms include heartburn, dysphagia (difficulty swallowing), and pain that can be mistaken for myocardial infarction. Endoscopy may reveal linear ulcers at the distal esophagus, often with exudate, erythema, or edema. In 50-60% of symptomatic patients, endoscopy is normal. Biopsy is required if clinically suggestive of reflux esophagitis, even if endoscopy is normal.
• Diagnosis: Clinical presentation (heartburn, regurgitation), endoscopy, and histological examination are used.
• Histopathology: Common findings include basal cell hyperplasia, intraepithelial inflammatory cells, and Barrett's esophagus (transformation of squamous epithelium into columnar epithelium, which can transform to cancer).
• Treatment: Motility promoting drugs, H2 receptor antagonists, proton pump inhibitors, and surgery to reduce hiatal hernia.

Peptic Ulcer (PU)

• Definition: An erosion of GI epithelium caused by acid-peptic juices. It is typically chronic and solitary.
• Causes: Helicobacter pylori infection, Nonsteroidal anti-inflammatory drug (NSAID) use, Zollinger-Ellison syndrome (gastrin-secreting tumor), alcohol, smoking, and corticosteroids.
• Pathophysiology:
  • H. pylori related ulcers: Produces urease (protection from acid), protease (breaks down glycoproteins in gastric mucus), and phospholipase (damages epithelial cells, may release leukotrienes). Attracts neutrophils, resulting in epithelial cell destruction.
  • NSAIDs induced ulcers: Gastric mucosa protects itself from acid with a mucus layer, stimulated by prostaglandins. NSAIDs block cyclooxygenase-1 (COX-1), essential for prostaglandin production.
• Common Sites: Duodenum, antrum, lesser curvature, gastroesophageal junction (GE junction). Duodenum is the most common site, 4 times more likely than the stomach.
• Clinical Picture: Abdominal pain (typically epigastric), strongly correlated with mealtimes. Pain relief by eating, nausea and vomiting, weight gain (duodenal ulcer), hematemesis, and melena.
• Treatment: Antibiotics (if H. pylori induced), proton pump inhibitors, discontinuation of NSAIDs and corticosteroids, and smoking cessation.

Colon Cancer

• Definition: Primary epithelial malignancy arising in the colorectum. Adenocarcinomas are the most prevalent type.
• Prevalence: Second or third most common cancer and cause of cancer deaths in men and women (98% adenocarcinomas).
• Demographics: More common in men than women. Peak age is 60-79 years, < 20% of cases occur before age 50. Rare before age 40, unless predisposing syndromes exist.
• Sites: Sigmoid colon and rectum are most common sites.
• Etiology: Risk factors include older age, obesity, physical inactivity, alcohol consumption, inflammatory bowel disease, family history of colorectal neoplasia, dietary risk factors (low vegetable fiber, increased beef, reduced vitamins A, C, and E), and some polyposis syndromes (APC gene).
• Pathophysiology: Low fiber prolongs transit time allowing toxic by-products to stay in contact with colonic mucosa. Beef consumption increases bile acid production, potentially converted to carcinogens.
• Clinical Features: Screening includes colonoscopy and occult blood tests. Symptoms can include right-sided tumors causing anemia, vague abdominal pain, left-sided tumors causing changes in bowel habits (diarrhea or constipation), and rectal bleeding.
• Metastases: 60% of patients have lymph node or distant metastases at diagnosis. Common metastatic sites are regional lymph nodes, liver, peritoneum, lung, and ovaries.
• Prognosis: 5-year survival rate is 40-60%, with most recurrences within 2 years.
• Treatment: Surgical excision followed by chemotherapy and/or radiotherapy.

This quiz explores the key aspects of Gastroesophageal Reflux Disease (GERD), including its definition, etiology, clinical features, and diagnosis. Test your understanding of how GERD affects the esophagus and the common symptoms associated with it.