*wierum is the concatenation of wie rum, which is the standard – not really colloquial any more – short form of wie herum ‘which way/orientation’. If it appears in a question, the answer will likely contain so (he)rum.
The writer probably wrote it as a single word because of the similar interrogative particles worum and warum or wieso, which all have the same counterpart darum. The wo-/da- pattern is very common in particular.
Other compounds ending in -rum could have contributed as well, of course.
Maybe German orthography will develop that way and some day *wierum and *sorum will be listed in dictionaries, but for now the conventional spelling is with two words, although you could not infer that from its pronunciation.