Iowa Code § 226.18

The director may investigate the mental condition of any patient and shall discharge any person, if, in the director’s opinion, the person is not mentally ill, or can be cared for after discharge without danger to others, and with benefit to the patient. In determining whether the patient shall be discharged, the recommendation of the superintendent shall be secured. If the director orders the discharge of an involuntarily hospitalized patient, the discharge shall be by the procedure prescribed in section 229.16. The power to investigate the mental condition of a patient is merely permissive, and does not repeal or alter any statute respecting the discharge or commitment of patients of the mental health institutes.