Missouri Revised Statutes Title XXX. Domestic Relations § 455.528. Modification of orders, who may file, when--termination--order not res judicata, when

1. After notice to the parties and the guardian ad litem or court-appointed special advocate and hearing, the court may modify an order of protection of a child at any time, upon subsequent motion filed by either party, the guardian ad litem, or the court-appointed special advocate together with an affidavit showing a change in circumstances sufficient to warrant the modification. All full orders of protection of a child shall be final orders and appealable and shall be for a fixed period of time not to exceed one hundred eighty days except as otherwise provided herein.

2. Any order for child support, custody, temporary custody, visitation or maintenance entered under sections 455.500 to 455.538 shall terminate prior to the time fixed in the order upon the issuance of a subsequent order pursuant to chapter 452, or any other Missouri statute.

3. No order entered pursuant to sections 455.500 to 455.538 shall be res judicata to any subsequent proceeding, including, but not limited to, any action brought under chapter 452.