Birchat Asher Yatzar
After relieving oneself, one is obligated to say the bracha of Asher Yatzar. Chazal instituted that one should recite Asher Yatzar after relieving oneself. The bracha was instituted for a person to give praise to Hashem for creating man with great wisdom. 
- Any time one goes to the bathroom (urinating or moving one's bowels) one is obligated to say the bracha of Asher Yatzar.Asher Yatzar is said every time that one releases excrement, even if it was a minute amount  This applies to both solid and liquid waste.
- One should recite asher yatzar after using the bathroom, even if he only went to check if he needed to use such as before davening.
- If no water is available to wash one's hands after relieving oneself, one should wipe one's hands on a piece of cloth or rub them against a hard surface such as a wall, and then recite Asher Yatzar. Later, when water becomes available, one should wash one's hands, but not repeat Asher Yatzar. 
Who is Obligated?
- Women are obligated to say Asher Yatzar as well.
- One should train his children to recite asher yatzar after using the bathroom.
- A person who still feels an urge to go to the bathroom again immediately after using the bathroom (diarrhea), should only say Asher Yatzar when he feels like he has cleared his bowels. One who feels the need to urinate immediately after urinating because of cold weather however, should recite asher yatzar anyway.
- One who urinates to get his urine tested should still say Asher Yatzar.
- Some poskim hold that you should not recite asher yatzar if there was blood in your excrement.
- One who is on a catheter, should recite asher yatzar, each time he feels that he has finished relieving himself.
If one Didn't Recite it Immediately
- One should say Asher Yatzar immediately after using the bathroom. However, if one did not say it immediately, many authorities hold that one can still say it for 72 minutes after going to the bathroom. Yet, other authorities say that one should not say it if 30 minutes past after going to the bathroom.
- If one used the bathroom and forgot to say Asher Yatzar and then used the bathroom again, only one bracha should be recited to cover both uses. Additionally, the Aruch HaShulchan says that if one went to the bathroom but forgot to say Asher Yatzar and subsequently needed to relieve oneself again, one should first relieve oneself and then say one bracha of Asher Yatzar 
- If a person is unsure whether he recited Asher Yatzar or not, he should not recite it. One may however, think the beracha in his head without reciting the words.
Asher Yatzar vs. Other Berachot
- If one uses the bathroom and additionally needs to recite boreh nefashot on food that he ate, asher yatzar should be recited first.
- If one uses the bathroom and then needs to recite asher yatzar as well as birkat hamazon or al hamichya, birkat hamazon or al hamichya take precedence.
- One may recite asher yatzar after the beracha of hamapil if he uses the bathroom.
- If one left the bathroom and then heard thunder or saw lightning before reciting asher yatzar, he should recite the beracha on the thunder or lightning because the time for those passes quickly.
Asher Yatzar as Part of Birchot HaShachar
- In the morning, one who goes to the bathroom should make the bracha of Asher Yatzar. If one slept (more than 30 minutes) then, according to Ashkenazim, one should make the bracha of Asher Yatzar even if one did not go to the bathroom.  One must have slept in one's bed for at least a half hour after halachic midnight.
- If one woke in the middle of the night and went to the bathroom, one should make Asher Yatzar then and another Asher Yatzar in the morning. 
- Although elokai neshama is not a beracha hasemucha lachaverta, one should still make an effort to recite it immediately after asher yatzar.
Understanding Asher Yatzar
- Asher Yatzar is an interesting Bracha because it never directly addresses the topic that it is about. One reason for this type of formulation is because it is not respectful to talk about relieving oneself overtly 
- A lot of meaning is contained within Asher Yatzar, for example, as we have seen there are 45 words corresponding to the numerical value of the word "ADAM" 
- Numerous explanations are given for the word beChachma. Rashi  explains based on Bereishit Rabba 1:4 that it is referring to the fact that Hakadosh Baruch Hu can keep air inside a person even though we have so many holes in our bodies. Tosafot  explains that it refers to the fact that G-d created man's sustenance before he created him. The Maharsha  explains that it is referring to man, and that he was created as an intelligent being. The Lavush explains that it refers to the many different processes that are involved in man's digestion and excretion; including taking in the food, holding the food, absorbing the nutrients, and excreting the waste 
- Nekavim mainly refers to the mouth and the organ used for excretion but is written twice to include every orifice.
- Chalulim refers to the inner organs that they remain closed and don't break open.
- While sephardim recite the yisatem before yipate'ach, Ashkenazim reverse that order and recite yipate'ach before yisatem.
- Although some authorities conclude the beracha rofeh cholei kol basar umafli laasot, this is not the common practice. Rather we conclude rofeh chol basar umafli laasot
- Ten Minute Halacha on The Beracha of Asher Yatzar by Rabbi Aryeh Lebowitz
- Article on The Laws and Nature of Asher Yatzar by Rabbi Moshe Taragin
- Gemara Berachot 60b, S”A 7:1, Ben Ish Chai Vayetseh #15
- S”A 7:1 based on a statement of Abaye in Brachot 60b he writes that anytime one goes to the bathroom one is obligated to say Asher Yatzar.
- Shulchan Aruch 7:4, Aruch HaShulchan 7:5, Teshuvot Harosh 4:1
- Aruch Hashulchan 7:1, Shulchan Aruch 7:4
- Yalkut Yosef Kitzur Shulchan Aruch 7:2
- Birkei Yosef 7:3, S”A 4:22
- Yalkut Yosef (Kitzur Shulchan Aruch 6:3), Ben Ish Chai Vayetze Halacha 15
- Yalkut Yosef (Kitzur Shulchan Aruch 6:3 and Dinei Chinuch Katan pg. 25)
- Mishna Brurah 7:2, Kaf Hachayim 7:2, Yalkut Yosef Kitzur Shulchan Aruch 7:3
- Kitzur Shulchan Aruch Yalkut Yosef 7:3
- Yalkut Yosef Kitzur Shulchan Aruch 7:6
- Shevet Hakehati 2:2. see also Yalkut Yosef Kitzur Shulchan Aruch 7:7
- Yalkut Yosef Kitzur Shulchan Aruch 7:8. see also Har Tzvi 1:6 and Tzitz Eliezer 8:1:3 Asher Yatzar for Catheter Insert on Dinonline.org
- Mishna Brurah 7:6 writes that one should be careful to recite Netilat Yadayim immediately after coming out of the bathroom so that one doesn't need to go again before one says Asher Yatzar and be caught in a dispute if one should recite one or two brachot. See Mishna Brurah 165:2 that one shouldn't delay Asher Yatzar to say it after Netilat Yadayim if one went to the bathroom and then is having a meal since one was already obligated to make Asher Yatzar before Netilat Yadayim. See Birur Halacha v. 2 siman 7 p. 43 who quotes Shaar Shlomo Zarafia that one can only recite Asher Yatzar up to toch kdei dibbur and many who disagree with him.
- Yalkut Yosef Kitzur Shulchan Aruch 6:3 and Halacha Brurah 7:5 write that one has up to 72 minutes after having used the bathroom, as long as one doesn't need it again. Similarly, Sh"t Yechave Daat 4:5 says that if you only remembered after 72 minutes, one should say the bracha without Shem U'Malchut. On the other hand, Sh"t Be'er Moshe (2:10 2; 4:4 1) writes that one could say the bracha even up to an hour or two after using the restroom, as long as one does not have the urge to once again use the restroom.
- Rivevot Efraim 8:2 writes that he originally ruled like Rav Ovadyah wrote in Yachave Daat (see previous note) that one may say it up until 72 minutes, however, after seeing many others who argued he said that one should be concerned for the opinion that says that one should not say it past 30 minutes after going to the bathroom. See also Rav Ovadyah in Yabia Omer 9:3 in his response to the author of the Revivot Efraim on this issue. See also Ben Ish Chai (Vayetze #12) who writes that one should not say Asher Yatzar 30 minutes after having gone to the bathroom. This is also the opinion of Rav Ben Tzion Abba Shaul (Or LeTzion 2:1:19), but Rav Ovadia (Yabia Omer 9:OC:108:17) argues that had Rav Ben Tzion seen the Ritva in Pesachim, he would have agreed. See also Asher Yatzar... The Deadline by Rabbi Ari Enkin.
- Ritva Pesachim 46a s.v. viy writes that the expiration of Asher Yatzar is the amount of time it takes to walk 4 mil. He explains that even if a person goes to the bathroom in the morning he can say it in shul even though some time elapsed.
- Maharach Or Zaruah responsa n. 101 writes that the expiration of brachot achronot are connected to the time it takes to digest food since the bracha is connected to the enjoyment of having eaten food. However, Asher Yatzer isn't for that purpose. He doesn't know exact amount of time Asher Yatzar expires but it is certainly less than four hours.
- Shulchan Aruch 7:3 says that Asher Yatzar should be recited twice. However, Mishna Brura 7:6 writes that most acharonim disagree and say that only one beracha should be recited. This is the opinion of the Bach Siman 7, Taz 7:2, Kaf Hachayim 7:5, Yalkut Yosef Kitzur Shulchan Aruch 7:10 and Aruch HaShulchan 7:4.
- Aruch HaShulchan 7:4.
- Yalkut Yosef Kitzur Shulchan Aruch 7:13, Birkei Yosef 7:3
- Mishna Brura 7:2 says this based on tadir visheayno tadir, tadir kodem. Yalkut Yosef Kitzur Shulchan Aruch 7:9
- Yalkut Yosef Kitzur Shulchan Aruch 7:9
- Halichot Shlomo 20:44, Sh"t Yechave data 4:21, Sh"t Tzitz Eliezer 7:27, Sh"t beer Moshe 1:63
- Mishna Brura 227:12
- Rama 4:1 writes that one should make Asher Yatzar even if one did not go to the bathroom. Mishna Brurah 4:3 comments that this is only true if one slept at night. This is based on the pasuk: Emunatecha Rabba LeBekarim Chadashim, They are new every morning; great is your faithfulness (Eicha 3:23).
- Igrot Moshe 1:4:1, Kesot HaShulchan, 5:2
- Kaf HaChaim 4:9
- Mishna Brurah 4:3 writes that it is preferable to make Asher Yatzar after one goes to the bathroom and not to push it off until Davening, because it is likely one will one go again and then not have made an Asher Yatzar for having gone the first time.
- Mishna Brura 6:12, Yalkut Yosef Kitzur Shulchan Aruch 6:16
- Aruch HaShulchan 6:1
- Aruch HaShulchan 6:1
- Ben Ish Chai Vayetze: Halacha 15 as quoted in Rav Simcha Bunim Cohen, Laws of everyday living. This gematria is only accurate for Sephardim who have 45 words in their version of Asher Yatzar
- Berachot 60b "Umafli"
- Berachot 60b "asher"
- Berachot 60b "asher"
- Aruch HaShulchan 6:2 brings all of these explanations
- Bet Yosef 6:1, Aruch HaShulchan 6:2
- Rashi 60b s.v. sh'im, Bet Yosef 6:1
- Shulchan Aruch 6:1, Kaf Hachaim 6:1
- Mishna Brura 6:2
- Mishna Brura 6:5, Kaf Hachaim 6:1