what's an anal & rectal contraction?

Could somebody give me some how-to descriptions on these? LR.

Here are my impressions so far (5 months into the journey and progressing slowly -- no Super-O yet.) I'm sort of a "nuts & bolts mechanic" when it comes to Aneros so my way of saying this is different (more crude) than someone who just relaxes and lets all this happen on its own. Those guys relax and give 'minor hints' to their bod and good vibes happen.

Anal Contractions of the outer sphincter are either those I consciously initiate (voluntaries) or those that my bod does on its own (involuntaries) this is the basic move we all start with. I'm not yet clearly differentiating inner sphincter involuntaries from outer sphincter involuntaries and rectal contractions (which right now for me) are mostly involuntary (i.e. I don't yet have much voluntary rectal control -- most of my work in that area has to come from other pelvic muscle groups).

When all goes well, involuntary rectals and 'sucking' inner sphincter contractions precede my mini-O. These draw the Aneros upward and 'hug' it against my prostate. Note: this isn't the voluntary 'bearing down' move we use to expel stool. When involuntary rectals happen, the smooth muscle of the rectum and the muscles of the sphincter are sort of working backward from how they work during defecation.

Some guys report continuous cycling involuntaries of the sphincter and rectum ('autofuck'). I've seldom experienced that and it's been brief, just four or five cycles over three or four seconds. We probably need some posts of the details of this. 👿 😀 ❓ ❓

We have a few experienced forum members who are able to cross the "autonomic" boundary ( http://en.wikipedia.org/wiki/Autonomic_nervous_system ) and exercise conscious control over pelvic tissue and muscle groups that most of us are either unaware of or are unable to control. Those artisans are truly members of the 'Royalty of Aneros.' 😮 😮 😀 Makes me green with envy!

So to answer your question simply...

Rectal contractions are a bearing down – pushing out contraction. (Like when you take a dump or are taking a piss)
Anal contractions are a pulling in- tensing up type of contraction. (Like when emptying the last few drops of urine)

Hope this is helpful! 8)

FrostFire has the best answer; it's not confusing for a beginner.