Mo. Rev. Stat. § 199.270
Any time after commitment, the patient or any friend or relative having reason to believe that such patient no longer has contagious tuberculosis or that his discharge will not endanger public health, may institute proceedings by petition, in the circuit court of the county wherein the confinement exists, whereupon the court shall set the matter down for a hearing before him within fifteen days requiring the person or persons to whose care the patient was committed to show cause on a day certain why the patient should not be released. The court shall also require that the patient be allowed the right to be examined prior to the hearing by a licensed physician of his own choice, if so desired, and at his own personal expense. Thereafter all proceedings shall be conducted the same as on the proceedings for commitment with the right of appeal by either party as herein provided; provided, however, such petition for discharge shall not be brought or renewed oftener than once every six months.
(L. 1961 p. 518 § 7)