by jr2 » 09 Mar 2013, 15:40
tf.
not from the people i know of. The maximum diameter I've heard of a guy using is a 2-inch (50 mm) dilator, and he says after years of doing dilation (he's in his 50s now), he has had no problems with continence or fissures or hemorrhoids. In my opinion, 50 mm sounds kind of excessive for most people, and especially women, but it could just be that it looks so huge to me (i'm still on 15 to 18 mm). When standardized anal dilation is done by a physician under anesthesia it doesn't exceed 40 mm, and is probably closer to 35 mm for women.
As with anything, common sense is best applied, and listening to one's own anatomy is always the wisest choice. The idea being to get better circulation and release of muscle tension and spasms, and in the case of those suffering stenosis to get the actual canal opening to widen over time.
While there aren't any official studies I can point to, from what I've been able to gather, the key is patience, with gradual dilation over time, and that if anything, the muscle being slowly and gently dilated regularly probably gives it greater elasticity and flexibility and strength, like any other muscle in the body. Kind of like a form of yoga for the anus. The damage could conceivably be done, as in any exercise of any muscle, if the sphincter is required to stretch too much too quickly, without enough lubrication, and even some "warm up", which is why I do some massage first.