A patient with severe diarrhea presents with hypokalemia and metabolic acidosis. What is the most likely cause of the metabolic acidosis in this patient?

A Loss of bicarbonate ions in the stool ✓
B Increased production of lactic acid
C Decreased excretion of hydrogen ions by the kidneys
D Increased absorption of ammonia from the gut

Explanation

Severe diarrhea can lead to loss of bicarbonate ions in the stool, resulting in metabolic acidosis. The loss of bicarbonate ions reduces the buffering capacity of the blood, leading to an increase in hydrogen ion concentration and a decrease in pH.

Source

Harrison's Principles of Internal Medicine
Electrolytes and Acid-Base Balance Pathophysiology Gastrointestinal Disorders Hard MEDICAL Confidence: high