Enables carboxylesterase activity. Is expressed in adult head; embryonic midgut chamber; embryonic/larval midgut; and organism. Human ortholog(s) of this gene implicated in colorectal cancer and gastrointestinal system cancer. Orthologous to several human genes including CES1 (carboxylesterase 1); CES2 (carboxylesterase 2); and CES3 (carboxylesterase 3).