Chloride/bicarbonate exchanger. Mediates the efficient absorption of chloride ions in the colon, participating in fluid homeostasis. Plays a role in the chloride and bicarbonate homeostasis during sperm epididymal maturation and capacitation. Interacts with CFTR, SLC26A6 and SLC9A3R1 (By similarity). Interacts with PDZK1. Localized in sperm membranes. Midpiece of sperm tail. Colocalizes with CFTR at the midpiece of sperm tail (By similarity). Expression is significantly decreased in adenomas (polyps) and adenocarcinomas of the colon. N-glycosylation is required for efficient cell surface expression, and protection from proteolytic degradation. The disease is caused by variants affecting the gene represented in this entry. Belongs to the SLC26A/SulP transporter (TC 2.A.53) family.