Acts as a sodium-independent DIDS-sensitive anion exchanger mediating bicarbonate, chloride, sulfate and oxalate transport. May play a role in the maintenance of the electrolyte and acid-base homeostasis in the kidney, by acting as a distal excretory segment-specific anion exchanger, specifically chloride. Plays a major role in gastric acid secretion (By similarity). Expressed in the cytoplasm in recycling endosomes of medullary collecting duct cells and in acid-secreting gastric parietal cells. Targeted to the basolateral membrane in hypertonicity and potassium depletion (By similarity). Belongs to the SLC26A/SulP transporter (TC 2.A.53) family.