I have the same problem and went to the doctor. My doctor took a close look at me and performed a rectal examination. It didn't solve the problem, so the doctor says I have to keep getting these rectal examinations untill the twitching goes away.
Have you done anything about it yet? Or are you just going to procrastinate about it on an on-going basis?
**** guys can you just get serious for once? Welcome to the training forum, thankfully someone re-directed you to the right place, a grown man ain't need to be hearing that mess from no fools. It's actually a more deadly disease called "Ebol-AIDS". The cure is wall-sits, lots of em.