Etiology of Acute and Chronic Diarrhea

Introduction

Diarrhea is a common medical condition characterized by frequent, loose, and watery stools. It can be classified into acute and chronic forms, each with distinct etiologies, pathophysiology, and causative agents.

Acute Diarrhea: Definition and Pathophysiology

Acute diarrhea is defined as the sudden onset of loose stools lasting less than 14 days. It is typically caused by infections, dietary factors, or medication side effects. The pathophysiology involves an imbalance in intestinal fluid absorption and secretion, often triggered by toxins, inflammation, or altered motility.

Common Etiological Agents of Acute Diarrhea

Infectious Causes

• Bacterial: Escherichia coli, Salmonella, Shigella, Campylobacter jejuni
• Viral: Rotavirus, Norovirus, Adenovirus
• Parasitic: Giardia lamblia, Cryptosporidium, Entamoeba histolytica

Non-Infectious Causes

• Food intolerance (e.g., lactose intolerance)
• Medication-induced (e.g., antibiotics, laxatives)
• Inflammatory conditions (e.g., irritable bowel syndrome)

Chronic Diarrhea: Etiology and Pathophysiology

Chronic diarrhea lasts longer than four weeks and can be caused by underlying medical conditions such as inflammatory bowel diseases (IBD), malabsorption syndromes, or endocrine disorders.

Causes of Chronic Diarrhea

• Inflammatory Conditions: Crohn's disease, ulcerative colitis
• Malabsorption Syndromes: Celiac disease, pancreatic insufficiency
• Endocrine Disorders: Hyperthyroidism, diabetes mellitus

Conclusion

Understanding the etiology of acute and chronic diarrhea is essential for accurate diagnosis and treatment. Proper identification of infectious and non-infectious causes helps in effective management and prevention.