Intestinal enterocytes express Trpml3 specifically during the suckling period and accumulate TRPML3 protein in their specialized endolysosomal organelles.
You might try staining with an antibody against ferroportin (Fpn1; SLC40a1). The presence of this iron transport protein relates to these enterocytes' function in dietary iron uptake and makes duodenal enterocytes unique from other intestinal cells.
Just be careful with your staining-- most commercially available clones are raised against a cytoplasm-facing epitope. Good luck!