Manyoka (diarrhoea, dysentry) chirwere chinoita kuti tsvina ibude kakawanda yakaita mvura-mvura. Chirwere ichi chinoonekwa kana munhu achibuditsa tsvina yakaita muchururu katatu pazuva kana kanodarika. Manyoka anoitika kana matumbu achikundika kunwira mvura kana kuti achibuditsa mvura yakawandisa. Nguva zhinji manyoka anogona kupera ega pasina kurapwa. Manyoka anoratidzika nenzira dzinoti: Kunzwa kurutsa Kupisa Muviri Kurukutika Kusvotwa VaGwere vanoti mbiro (diarrhoea) kureva manyoka. Kinande inoti eripanza (v. scatter) kureva kumwararidza. Fananidzai nokuti kupandana. Mamwe mazwi: erituruka (v. have diarrhea) kuita manyoka.