Is a brocha necessary if one rewashes in the middle of a meal?

Shulchan Aruch rules that if a person must rewash his hands in the middle of a meal for any reason , he must recite a brocha. Other Achronim disagree and maintain that a brocha is not necessary. Mishnah Berurah offers a compromise ruling: If a person uses the bathroom for gedolim, touches excrement or leaves the meal for an extended break, he must rewash with a brocha. If he only touches a covered area, urinates, or changes a diaper without coming directly in contact with excrement, he should rewash without a brocha. Others reject this compromise and say that a person should follow one of the two views—either to always recite a brocha or to never recite one.

סי' קס"ד ס"ק יא-יד ביה"ל ד"ה לחזר ביאורים ומוספים דרשו 19

What is the proper procedure for one who goes to the bathroom before a meal?

A person who goes to the bathroom before a meal must wash for the brochos of Asher Yotzar and Netilas Yadayim. According to some Rishonim, one washing will not suffice. Their reasoning is as follows:  If Asher Yotzar would be recited after the washing, there would be a hefsek between washing and the brocha of Al Netilas Yadayim. If Asher Yotzar would be recited after the brocha of Al Netilas Yadayim, there would be a hefsek between the washing and the brocha of Hamotzi. To delay the Asher Yotzar until the bread is eaten is also inappropriate, since the person was already obligated to say the brocha before the meal. Therefore, these Rishonim  rule that he should wash twice. After the first washing he should say Asher Yotzar and after the second washing he should say Al Netilas Yadayim. The first washing should not be done according to the halachos of netilas yadayim. Otherwise, the second washing will be unnecessary and he will not be able to recite a brocha. Some poskim say that one should wash directly from the sink for the first washing and use a utensil for the second washing. Shulchan Aruch rules according to this opinion.

סי' קס"ה ס"א ס"ק א' ביאורים ומוספים דרשו 3

What was the Chafetz Chaim’s personal practice regarding Asher Yotzar and Al Netilas Yadayim? 

Other Rishonim hold that one may wash once and recite Al Netilas Yadayim followed by Asher Yotzar. They hold that Asher Yotzar is not a hefsek since it is a part of the taharah of the hands. Mishnah Berurah rules that if a person washed properly the first time or if there is a shortage of water, he may rely on this opinion. Others hold that one should follow this opinion l’chatchilah. It is recorded that the personal custom of the Chafetz Chaim was to only wash once and recite Al Netilas Yadayim followed by Asher Yotzar.

ס"ק ב' ביאורים ומוספים דרשו 4

• The Gemara states that a person can wash his hands in the morning according to all the halachos of netilas yadayim (for reasons of cleanliness) and stipulate (either verbally or in his mind) that he wants the netilah to cover any time he wants to eat throughout the day.

• The Achronim write that it is no longer customary to wash in the morning and stipulate that the netilah will cover eating throughout the day. They explain that it is difficult for us to keep our hands clean.

• If, during a meal, a person realizes that he touched an area of his body which is normally covered or that he scratched his head, he must rewash his hands.

• Would the Chafetz Chaim touch parshios of tefillin in the middle of a meal?

• May one recite a brocha after the first pour?

• Who should wash first?