Iowa Code § 630.17: Answers verified — petition taken as true.

The answers of all defendants shall be verified by their own oath, and not by that of an agent or attorney, and the court shall enforce full and explicit discoveries in such answers by process of contempt; or, upon failure to answer the petition, or any part thereof, as fully and explicitly as the court may require, the same, or such part not thus answered, shall be deemed true, and such order made or judgment rendered as the nature of the case may require.