The function of SLC26A3 (solute carrier family 26 member 3, ENSG00000091138) is as follows. Mediates chloride-bicarbonate exchange with a chloride bicarbonate stoichiometry of 2:1 in the intestinal epithelia (PubMed:16606687, PubMed:19321737, PubMed:22159084, PubMed:22627094). Plays a role in the chloride and bicarbonate homeostasis during sperm epididymal maturation and capacitation (By similarity). {ECO:0000250|UniProtKB:Q9WVC8, ECO:0000269|PubMed:16606687, ECO:0000269|PubMed:19321737, ECO:0000269|PubMed:22159084, ECO:0000269|PubMed:22627094}.