Shulchan Arukh Orach Chayim · Siman 7

English

The Laws of Reciting the Blessing of "Asher Yatzar" Throughout the Day After One Urinates. Containing 4 Se'ifim: Throughout the day, when one relieves themselves, whether urination or defecation, they should recite the "Asher Yatzar" blessing, but not "Al Netilat Yadayim" even if one wants to learn or pray immediately after. Rema: If one's hands were dirty because he wiped with them, even in such a case, one should not recite the blessing "Al Netilat Yadayim" (Sefer Mitzvot Ha-Gadol - siman 27, mitzvah 9)

English

If one urinated and did not brush off [any drops of urine with his hands] - even though he must recite Asher Yatzar, washing his hands is only necessary for [the sake of] cleanliness/hygiene or because of the notion of "Hikkon" (Amos 4:12) (i.e. preparation for the proper davening mindset).

English

One who urinated and then diverted his mind from urinating [further], and then later decided to urinate again - he needs to recite "Asher Yatzar" twice.

English

There is no specific amount of urinating required, because even if one urinates a single drop one must recite the ["Asher Yatzar"] blessing, because if one's opening would be blocked from releasing that drop, it would painful to him, and so he is required to give thanks.