why do they make a shehecheyanu by a bris in Israel if Tosafot says on amud bet that we don't because of Tza'ar l'Yenukah.
Avi Moshel, Yerushalayim Israel
Have a look at Shulchan Aruch Yoreh Deah 265:7 and the Be'er haGolah (15) and the Biur haGR"A (35-36) for a thorough discussion of the issues.
There are actually more reasons - besides Tsara d'Yenukah - given by the Rishonim for not saying Shehecheyanu at a Bris. There are three main reasons given: 1) Tsara d'Yenukah, 2) the baby is still a Safek Nefel, 3) it is not a Mitzvah m'Zman l'Zman (that comes at set intervals, like the holidays).
The Rashba in a Teshuvah (1:245) deals with all of these possible reasons and rejects them all. 1) is not a sufficient reason -because even in sadder situations there is sometimes a Berachah of Shehecheyanu, for instance when one's father is Niftar and he receives an inheritance. The Rashba says that Shehecheyanu is not on the Simchah of the event but on the benefit that the newborn brings to his parents. 2) is not sufficient - because we can rely on the Simanim of fetal development, such as hair and fingernails, that the child is not a Neifel. The Rashba says that if we are allowed to rely on these Simanim when it comes to making a Bris on Shabbos and doing Melachos, then certainly we are entitled to rely on them when it comes to making a Berachah. Finally 3) is not sufficient reason - because we find that Chazal instituted a Shehecheyanu for Pidyon ha'Ben, which is also not m'Zman l'Zman.
Interestingly, the Rashba himself, after presenting all his arguments against the Minhag of not saying Shehecheyanu, declares that since all of the Gedolim of his part of the world accept this Minhag he will also accept it.
The Vilna Gaon, however, in his Bi'ur ha'GR"A, seems to reject the Minhag completely. Indeed, Rav Moshe Sternbuch in his Sefer "Hilchos ha'GR"A u'Minhagav" says that this is the opinion of the GR"A l'Ma'aseh. Apparently the Ashkenazim of Eretz Yisrael make the Berachah for the same reason that they say Birkas Kohanim every day of the year - they are following a Minhag that was laid down by Talmidim of the GR"A who came to Eretz Yisrael and founded the first Ashkenazi communities here.
This is not a Psak Halachah