What type of renal tubular acidosis is associated with increased oxalate reabsorption due to Crohn's disease?

In the context of renal tubular acidosis (RTA) associated with increased oxalate reabsorption due to Crohn's disease, the correct answer refers to Type 2 RTA, or proximal renal tubular acidosis. This condition is characterized by a defect in proximal tubular bicarbonate reabsorption, which leads to metabolic acidosis.

Patients with Crohn's disease often experience malabsorption and excessive intestinal oxalate absorption. In Type 2 RTA, the impaired reabsorption of bicarbonate results in lower plasma bicarbonate levels, which can lead to compensatory mechanisms that attempt to maintain acid-base balance. When bicarbonate is lost, oxalate, which is typically reabsorbed in the intestine in conjunction with calcium, can be absorbed in excess, especially in the setting of increased intestinal permeability or altered absorption dynamics due to Crohn's disease. This increased reabsorption results in higher levels of oxalate being filtered by the kidneys, potentially leading to nephrolithiasis (kidney stones) due to calcium oxalate precipitation.

In summary, Type 2 renal tubular acidosis is linked to the physiological changes that occur in Crohn's disease, particularly the increased absorption of oxalate due to the