Stomach

The Human Stomach: Anatomy, Physiology, Disorders & Treatment Guide with FAQs

1. Introduction

• The stomach is a vital digestive organ responsible for breaking down food, secreting gastric juices, and aiding nutrient absorption.
• It plays a key role in digestion, immunity, and metabolic regulation.
• Common stomach disorders include gastritis, ulcers, acid reflux, and stomach cancer.

2. Anatomy of the Stomach

• Location: Upper left abdomen, between the oesophagus and small intestine.
• Structure:
  • Cardia: Entry point where food enters from the oesophagus.
  • Fundus: Stores undigested food and gases.
  • Body: Main digestion site where enzymes and acids break down food.
  • Pylorus: Regulates the passage of food into the small intestine.
• Layers:
  • Mucosa: Produces digestive enzymes and mucus.
  • Submucosa: Contains nerves and blood vessels.
  • Muscularis: Contracts to mix food.
  • Serosa: Protective outer layer.
• Blood Supply:
  • Celiac Artery & Gastric Arteries.

3. Physiology of the Stomach

• Digestion Process:
  • Food enters through the lower oesophageal sphincter (LES).
  • The stomach secretes hydrochloric acid (HCl) and pepsin to break down proteins.
  • Muscular contractions churn food into chyme, which moves into the small intestine.
• Gastric Secretions:
  • HCl: Activates enzymes and kills bacteria.
  • Pepsin: Breaks down proteins.
  • Intrinsic Factor: Aids vitamin B12 absorption.
  • Mucus: Protects the stomach lining from acid.
• Hormonal Regulation:
  • Gastrin: Stimulates acid production.
  • Ghrelin: Triggers hunger.

4. Common Disorders & Pathophysiology

A. Acid Reflux (Gastroesophageal Reflux Disease – GERD)

• Cause: Weak LES allows acid to backflow into the oesophagus.
• Symptoms: Heartburn, regurgitation, chest pain.

B. Gastritis (Stomach Lining Inflammation)

• Cause: H. pylori infection, NSAIDs, excessive alcohol.
• Symptoms: Upper abdominal pain, nausea, bloating.

C. Peptic Ulcers

• Cause: H. pylori, NSAID overuse, excessive acid production.
• Symptoms: Burning stomach pain, bleeding, vomiting blood.

D. Stomach Cancer (Gastric Cancer)

• Cause: Genetic mutations, H. pylori, smoking, processed foods.
• Symptoms: Persistent bloating, weight loss, difficulty swallowing.

E. Gastroparesis (Delayed Stomach Emptying)

• Cause: Diabetes, nerve damage, vagus nerve dysfunction.
• Symptoms: Nausea, vomiting, bloating, early fullness.

F. Food Poisoning & Stomach Infections

• Cause: Bacterial (E. coli, Salmonella), viral, or parasitic infections.
• Symptoms: Diarrhoea, cramps, fever, vomiting.

G. Hiatal Hernia

• Cause: The stomach pushes through the diaphragm.
• Symptoms: Acid reflux, bloating, difficulty swallowing.

5. Signs & Symptoms of Stomach Disorders

• Early Symptoms:
  • Mild heartburn, bloating.
  • Loss of appetite, nausea.
• Advanced Symptoms:
  • Severe abdominal pain.
  • Blood in stool or vomit.
  • Difficulty swallowing.
• Red Flags:
  • Unexplained weight loss.
  • Persistent vomiting or dark stools.
  • Sudden, severe stomach pain.

6. When to See a Doctor

• Frequent acid reflux or persistent stomach pain.
• Symptoms that don’t improve with diet or medication.
• Difficulty eating or swallowing food.

7. Emergency Signs Requiring Immediate Care

• Vomiting blood or black stools.
• Sudden, severe pain (possible perforation or rupture).
• Severe dehydration due to continuous vomiting or diarrhoea.

8. Diagnostic Process

• Clinical Examination: Checks for tenderness, bloating, and pain location.
• Laboratory Tests:
  • H. pylori Test: Detects bacterial infection.
  • Complete Blood Count (CBC): Identifies anaemia (possible ulcer bleeding).
• Imaging Tests:
  • Upper Endoscopy (Gastroscopy): Visualises stomach lining.
  • Barium Swallow X-ray: Identifies structural abnormalities.
• Specialist Procedures:
  • Biopsy: Confirms cancer or H. pylori infection.
  • Gastric Emptying Study: Diagnoses gastroparesis.

9. Likely Diagnoses

• Acid Reflux (GERD).
• Gastritis or Peptic Ulcer Disease.
• H. pylori Infection.
• Gastroparesis.
• Stomach Cancer.

10. Treatment Options

A. Medications

• For Acid Reflux & Ulcers:
  • Proton Pump Inhibitors (Omeprazole, Esomeprazole).
  • H2 Blockers (Ranitidine, Famotidine).
• For H. pylori Infection:
  • Antibiotics (Amoxicillin, Clarithromycin).
• For Stomach Cramps & Nausea:
  • Antispasmodics (Dicyclomine, Hyoscyamine).
  • Anti-emetics (Ondansetron, Metoclopramide).
• For Gastric Motility Issues:
  • Prokinetics (Domperidone, Metoclopramide).
• Approximate Medication Costs (USD):
  • PPIs & H2 Blockers: $10–$100/month.
  • H. pylori Treatment (Triple Therapy): $50–$300 per course.

B. Surgical/Procedural Interventions

• Fundoplication (For Severe GERD) ($10,000–$30,000).
• Gastrectomy (For Stomach Cancer) ($20,000–$50,000).
• Endoscopic Therapy (For Bleeding Ulcers) ($5,000–$15,000).

C. Lifestyle Modifications & Home Remedies

• For GERD & Acid Reflux:
  • Eat smaller meals, avoid lying down after eating.
  • Reduce spicy, fatty foods, caffeine, and alcohol.
• For Gastritis & Ulcers:
  • Avoid NSAIDs and excessive salt intake.
  • Probiotic-rich foods (yogurt, kefir) for gut health.
• For Bloating & Gas:
  • Stay hydrated, eat slowly, and avoid carbonated drinks.

11. Precautions & Prevention

• Eat a balanced diet with fibre-rich foods.
• Limit alcohol & smoking to prevent ulcers and reflux.
• Manage stress and avoid excessive NSAID use.
• Regular screenings if at high risk for stomach cancer.

12. Prognosis & Recovery

• GERD & Gastritis: Manageable with medication and diet.
• Peptic Ulcers: Heal within 6–8 weeks with treatment.
• Stomach Cancer: Early detection improves survival.

13. Cost of Treatment

• Endoscopy (Gastroscopy): $500–$3,000.
• H. pylori Treatment: $50–$300.
• GERD Surgery: $10,000–$30,000.
• Cancer Treatment (Chemotherapy & Surgery): $50,000+.

14. Frequently Asked Questions (FAQs)

1. Why does my stomach burn after eating? – Likely acid reflux, gastritis, or ulcers.
2. Can stress cause stomach problems? – Yes, stress increases acid production.
3. Are probiotics good for stomach health? – Yes, they support gut microbiome balance.
4. Can I heal gastritis naturally? – Yes, by avoiding triggers, eating probiotics, and reducing stress.
5. What foods trigger acid reflux? – Spicy, fried, citrus, caffeine, and alcohol.