In our house it was the yiddish word tuches too. The closest to English pronunciation is "took-us", and it means buttocks in yiddish. When I hear it now it brings back some feelings of embarrassment, but not excitement. In terms of RT's and suppositories, even when we were very young my folks would not have said "we need to put this in your tuches", they would have used the word rectum. You might get spanked on your tuches, but you had your temperature taken in your rectum. I have read that "tuches" might be the word that the word "tush" was derived from.