GIT GASTRITIS

Gastritis and Related Conditions

1. Gastritis

Definition

  • Inflammation of the gastric mucosa caused by various irritants or pathological conditions.

Pathophysiology

  • Gastritis occurs due to an imbalance between aggressive factors (e.g., acid, pepsin) and protective factors (e.g., mucus, bicarbonate, prostaglandins).

  • Common mechanisms include:

    • Direct mucosal injury by irritants (e.g., NSAIDs, alcohol).

    • Immune-mediated inflammation (e.g., autoimmune gastritis).

    • Infection (e.g., H. pylori).

Types/Classification

  1. Acute Gastritis: Sudden onset due to irritants or infections.

  2. Chronic Gastritis: Prolonged inflammation, commonly caused by H. pylori or autoimmune disorders.

Clinical Features

  • Epigastric pain or burning.

  • Nausea, vomiting.

  • Hematemesis or melena in severe cases.

Complications

  • Peptic ulcer disease (PUD).

  • Atrophic gastritis.

  • Gastric cancer.

Treatment

  • Pharmacological:

    • PPIs or H2-receptor antagonists to reduce acid production.

    • Eradication therapy for H. pylori.

  • Non-Pharmacological:

    • Avoidance of NSAIDs, alcohol, and smoking.

    • Dietary modifications (avoid irritant foods).

2. Helicobacter pylori Gastritis

Definition

  • Gastritis caused by infection with H. pylori, a spiral-shaped, gram-negative bacterium that colonizes the gastric mucosa.

Pathophysiology

  • H. pylori produces urease, which converts urea to ammonia, neutralizing stomach acid and damaging the mucosa.

  • Chronic infection leads to:

    • Increased acid secretion → duodenal ulcers.

    • Atrophy and reduced acid secretion → gastric ulcers and cancer.

Clinical Features

  • Often asymptomatic.

  • Symptoms of gastritis or PUD.

Complications

  • Peptic ulcer disease.

  • Gastric adenocarcinoma.

  • MALT lymphoma.

Diagnosis

  • Urea breath test.

  • Stool antigen test.

  • Endoscopy with biopsy (rapid urease test or histology).

Treatment

  • Triple therapy: PPI + clarithromycin + amoxicillin or metronidazole.

  • Quadruple therapy: PPI + bismuth + tetracycline + metronidazole (for resistant strains).

3. Autoimmune Gastritis

Definition

  • A chronic condition in which the immune system attacks the gastric parietal cells and intrinsic factor, leading to mucosal atrophy and vitamin B12 deficiency.

Pathophysiology

  • CD4+ T cells target parietal cells → reduced gastric acid (hypochlorhydria) and intrinsic factor production.

  • Leads to impaired vitamin B12 absorption → pernicious anemia.

Clinical Features

  • Non-specific: Nausea, vomiting, bloating, epigastric pain.

  • B12 deficiency symptoms: Fatigue, glossitis, neuropathy, megaloblastic anemia.

Complications

  • Pernicious anemia.

  • Gastric adenocarcinoma.

  • Neuropsychiatric disorders due to B12 deficiency.

Diagnosis

  • Anti-parietal cell or anti-intrinsic factor antibodies.

  • Elevated serum gastrin levels.

  • Endoscopy: Atrophic mucosa.

Treatment

  • Lifelong vitamin B12 supplementation.

  • Regular surveillance for gastric cancer.

4. Peptic Ulcer Disease (PUD)

Definition

  • Ulcers in the gastric or duodenal mucosa due to acid-peptic injury.

Pathophysiology

  • Disruption of mucosal defenses by:

    • Increased gastric acid and pepsin secretion (H. pylori, Zollinger-Ellison syndrome).

    • Reduced mucosal protection (NSAIDs, stress, smoking).

Clinical Features

  • Epigastric pain:

    • Gastric ulcer: Pain worsens with food.

    • Duodenal ulcer: Pain relieved by food.

  • Nausea, bloating.

  • Hematemesis or melena in severe cases.

Complications

  • Bleeding.

  • Perforation.

  • Gastric outlet obstruction.

Treatment

  • Eradication of H. pylori (if present).

  • PPIs or H2 blockers.

  • Discontinuation of NSAIDs.

  • Surgery for complications (e.g., perforation).

5. Gastric Ulcers vs. Duodenal Ulcers

FeatureGastric UlcerDuodenal Ulcer

Location

Stomach (lesser curvature common)

Proximal duodenum

Pain

Worsens with food

Relieved by food

Acid Secretion

Normal or reduced

Increased

Complications

Malignancy risk higher

Rarely malignant

H. pylori Role

70% of cases

90% of cases

6. Gastric Polyps

Definition

  • Benign or malignant growths protruding from the gastric mucosa.

Types

  1. Hyperplastic Polyps:

    • Reactive, associated with chronic gastritis.

    • Rarely malignant.

  2. Fundic Gland Polyps:

    • Associated with PPI use or familial adenomatous polyposis (FAP).

    • Rarely malignant.

  3. Adenomatous Polyps:

    • Pre-malignant, risk of gastric adenocarcinoma.

Clinical Features

  • Often asymptomatic.

  • May present with dyspepsia, bleeding, or anemia.

Diagnosis

  • Endoscopy with biopsy to differentiate benign from malignant polyps.

Treatment

  • Hyperplastic polyps: No treatment if small; remove large or symptomatic polyps.

  • Adenomatous polyps: Removal and surveillance for malignancy.