I purged twice in a two year period. I purged out of fear - of getting caught, of the consequences (losing home, spouse, children), but mostly I was afraid of myself. I was afraid to admit who I was (and am).
The times that I purged were in the middle of very depressive episodes where I was doing a great deal of self-loathing. I didn't stop to think what I was doing - typical of depressive behavior, I just plunged in and did it. Each time, after a few weeks, I'd recover and say to myself, what did I do?
YMMV, though. I was brought up in a very conservative Christian home where any type of "oddball" behavior was fraught with criticism and discipline. This has made my CD (and later, TS) journey worse. I have yet to reconcile Christianity and being TS, and as a result, tend to rock back and forth between "I am" and "I'm not" depending upon my spiritual "walk" at the time. At the times I purged, I was in a "I'm not" period, and this (no doubt) contributed to the "need to purge".
Over the last year, though, I decided that I will NOT purge no matter what, until I've come to some conclusions over a period of months.
Thanks for starting this thread. It's nice to be able to vent some frustrations!
Carol