shitting vs voiding

shitting and voiding both are nouns.

Word	Noun	Adjective	Verb	Adverb
shitting	Yes	No	No	No
voiding	Yes	No	No	No

As nouns, voiding is a hypernym of shitting; that is, voiding is a word with a broader meaning than shitting:

Other hypernyms of shitting include elimination, evacuation, excreting, excretion.

shitting (noun)	voiding (noun)
the elimination of fecal waste through the anus	the bodily process of discharging waste matter