Mo. Rev. Stat. § 631.160
Whenever any respondent detained involuntarily under this chapter in an alcohol or drug abuse facility is found during the detention period to be in need of medical care and treatment provided in a hospital, which in the opinion of a licensed physician must be attended to immediately, the respondent may be transferred to a hospital for care and treatment. The hospital may perform surgery or provide medical treatment with the respondent's consent, or without his consent under the provisions of section 431.063 or chapter 475. If the respondent's detention period has not expired at the completion of the hospital care and treatment, then the respondent shall be returned to the alcohol or drug abuse facility to complete the detention for treatment and rehabilitation. The respondent may have detention periods continued while in the hospital under the provisions of this chapter.
§ 631.160, RSMo