Exhibit 3.157 CERTIFICATE OF FORMATION OF WATHENA HEALTHCARE AND REHABILITATION CENTER, LLC This Certificate of Formation of Wathena Healthcare and Rehabilitation Center, LLC is being duly executed and filed by an authorized person to form a limited liability company under the Delaware Limited Liability Company Act (6 Del.C. Section 18-101, et. seq.). FIRST. The name of the limited liability company formed hereby is: WATHENA HEALTHCARE AND REHABILITATION CENTER, LLC SECOND. The address of the registered office and the name and the address of the registered agent of the limited liability company required to be maintained by Section 18-104 of the Delaware Limited Liability Company Act is: NATIONAL REGISTERED AGENTS, INC. 9 EAST LOOCKERMAN STREET, SUITE 1B DOVER, KENT COUNTY, DELAWARE, 19901 IN WITNESS WHEREOF, the undersigned has executed this Certificate of Formation as of November 1, 2004. /s/ Cindy M. VanDran ---------------------------------------- Cindy M. VanDran Authorized Person