Generally not. PLCs are designed to be as reliable and fault tolerant as possible, so they don't allow recursion (along with a bunch of other things, like direct memory access with pointers[1]) since it's so easy to accidentally make something either take a really long time, or fail to terminate. You can fake it by piping an output into a variable which is also used as an input, but this makes it explicit that the last value is used then the next value stored, rather than multiple steps of recursion happening in one scan.
Generally the kind of software you develop in structured text doesn't need recursion anyway.
As someone not familiar with this, why not? Can't you just draw a line from output to input?