What type of metabolic acidosis is likely caused by chronic diarrhea?

Chronic diarrhea leads to non-anion gap metabolic acidosis primarily due to the excessive loss of bicarbonate through the intestines. When the gastrointestinal tract is unable to reabsorb bicarbonate effectively, or when bicarbonate is lost alongside other electrolytes in the feces, the body’s bicarbonate levels decrease. This reduction results in a lowered pH, characteristic of metabolic acidosis.

In non-anion gap metabolic acidosis, the main underlying issue is the loss of bicarbonate without the accumulation of organic acids or additional unmeasured anions. In the case of diarrhea, especially if it is prolonged, the loss of bicarbonate can be significant and lead to a compensatory response from the kidneys, which will attempt to retain bicarbonate and excrete hydrogen ions. This mechanism highlights why patients experiencing chronic diarrhea often present with a non-anion gap metabolic acidosis, as there is no production of excess acids to complicate the acid-base balance.

The other forms of metabolic acidosis featured in the choices reflect different underlying causes and mechanisms. Anion gap metabolic acidosis typically arises from conditions such as lactic acidosis, ketoacidosis, or renal failure, where there is an accumulation of unmeasured anions. Respiratory acidosis