Mo. Rev. Stat. § 631.110: Discharge of voluntary client, when — denial of request for release, when, effect.

1. The head of an alcohol or drug abuse facility may discharge any voluntary client whose continued involvement in the program is determined to be either no longer beneficial to the client or an ineffective use of the facility.

2. The head of an alcohol or drug abuse facility shall release any client who requests his release in writing or whose release is requested by his guardian or parent, if the parent applied for admission; except that, if the head of the facility believes the client is presenting a likelihood of serious harm as a result of the alcohol or drug abuse, the head of the facility may deny the request for release. If the request for release is denied, the head of the facility may detain the client only if he immediately initiates the involuntary detention procedure set out in this chapter.