# Under normal conditions, how tight is the average sphincter? **URL:** \ **Category:** Factual Questions\ **Created:** [October 12, 2004, 6:42pm UTC](https://boards.straightdope.com/t/under-normal-conditions-how-tight-is-the-average-sphincter/268853 "2004-10-12T18:42:04Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![Chairman\_Pow](https://avatars.discourse-cdn.com/v4/letter/c/838e76/32.png) [@Chairman\_Pow](https://boards.straightdope.com/u/Chairman_Pow)\ **Post date:** [October 12, 2004, 6:42pm UTC](https://boards.straightdope.com/t/under-normal-conditions-how-tight-is-the-average-sphincter/268853/1 "2004-10-12T18:42:04Z")
Watertight? Airtight? Is there an objective measurement? ---
**Author:** ![silenus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/silenus/32/166_2.png) [@silenus](https://boards.straightdope.com/u/silenus)\ **Post date:** [October 12, 2004, 6:50pm UTC](https://boards.straightdope.com/t/under-normal-conditions-how-tight-is-the-average-sphincter/268853/2 "2004-10-12T18:50:38Z")
Is a duck’s butt watertight? 😃 The human sphincter is normally water and air tight. Otherwise there would be…leakage. :eek: ---
**Author:** ![Padeye](https://avatars.discourse-cdn.com/v4/letter/p/a9a28c/32.png) [@Padeye](https://boards.straightdope.com/u/Padeye)\ **Post date:** [October 12, 2004, 7:21pm UTC](https://boards.straightdope.com/t/under-normal-conditions-how-tight-is-the-average-sphincter/268853/3 "2004-10-12T19:21:50Z")
Asseholes are not airtight under all circumstances otherwise we wouldn’t have farts. The only way you can get an objective measurement is to specify a pressure. My timex may say water resistant but I’d best not duct tape it to the hull of a submarine despite John Cameron Swayzy’s (sp?) motorboat demonstrations. Also some materials can get by seals better than others. It’s not that difficult to make a watertight seal because of water’s surface tension. Oil is a different matter and can be much harder to seal. The plumbing in your house is normally bone dry on the ouside but how many times have you seen a hydralic system that didn’t have a coating of dust stuck to leaked fluid at connections and seals? As for how this applies to the OP I’ll just say “Olestra™.” ---
**Author:** ![slortar](https://avatars.discourse-cdn.com/v4/letter/s/6bbea6/32.png) [@slortar](https://boards.straightdope.com/u/slortar)\ **Post date:** [October 12, 2004, 8:03pm UTC](https://boards.straightdope.com/t/under-normal-conditions-how-tight-is-the-average-sphincter/268853/4 "2004-10-12T20:03:17Z")
Perhaps we could mail some grip strength devices to a random sampling of people and find out? “Wow, Slortar! 300 lbs! Your ass is strong!” ---
**Author:** ![Crandolph](https://avatars.discourse-cdn.com/v4/letter/c/7cd45c/32.png) [@Crandolph](https://boards.straightdope.com/u/Crandolph)\ **Post date:** [October 12, 2004, 8:30pm UTC](https://boards.straightdope.com/t/under-normal-conditions-how-tight-is-the-average-sphincter/268853/5 "2004-10-12T20:30:37Z")
In his autobiography _Confessions of a Raving, Unconfined Nut_, Paul Krassner includes the text of a semi-ranting tract a doctor (IIRC) once gave him extolling the virtues and value of the anal sphincter. The point seemed to be to appreciate this lowly bit of tissue more. I just looked in the index under “sphincter” and there weren’t any listings, so you’ll have to find it yourself. An amusing little read. It lists airtight and watertight as two big plusses. Aren’t there other sphincters in the human body as well? We all assumed anal… ---
**Author:** ![Earthworm\_Jim](https://avatars.discourse-cdn.com/v4/letter/e/f07891/32.png) [@Earthworm\_Jim](https://boards.straightdope.com/u/Earthworm_Jim)\ **Post date:** [October 12, 2004, 9:08pm UTC](https://boards.straightdope.com/t/under-normal-conditions-how-tight-is-the-average-sphincter/268853/6 "2004-10-12T21:08:46Z")
> [@Padeye](#): > > As for how this applies to the OP I’ll just say “Olestra™.” [minor hijack] Olestra may have gotten a bum rap, as it were. Reason Magazine published an interesting [article](http://www.findarticles.com/p/articles/mi_m1568/is_3_35/ai_102908459) regarding the Center for Science in the Public Interest in July 2003. Just FYI, is all. ---
**Author:** ![vetbridge](https://avatars.discourse-cdn.com/v4/letter/v/b5e925/32.png) [@vetbridge](https://boards.straightdope.com/u/vetbridge)\ **Post date:** [October 12, 2004, 11:52pm UTC](https://boards.straightdope.com/t/under-normal-conditions-how-tight-is-the-average-sphincter/268853/7 "2004-10-12T23:52:24Z")
'nother slight hijack: In _Ball Four_ (IIRC) I read about a sportscaster who said something like this in describing a nervous pitcher, “He’s so tight you couldn’t drive a toothpick up his ass with a sledgehammer”. Now _that’s_ tight! ---
**Author:** ![DougC](https://avatars.discourse-cdn.com/v4/letter/d/7feea3/32.png) [@DougC](https://boards.straightdope.com/u/DougC)\ **Post date:** [October 13, 2004, 4:42am UTC](https://boards.straightdope.com/t/under-normal-conditions-how-tight-is-the-average-sphincter/268853/8 "2004-10-13T04:42:35Z")
- - - If you can pick nickels up off the floor with it, you should probably relax more often. ~ ---
**Author:** ![KGS](https://avatars.discourse-cdn.com/v4/letter/k/90ced4/32.png) [@KGS](https://boards.straightdope.com/u/KGS)\ **Post date:** [October 13, 2004, 5:12am UTC](https://boards.straightdope.com/t/under-normal-conditions-how-tight-is-the-average-sphincter/268853/9 "2004-10-13T05:12:51Z")
> [@Crandolph](#): > > Aren’t there other sphincters in the human body as well? We all assumed anal… From [Britannica online](http://www.britannica.com/eb/article?tocId=9069101): > [@](#): > > Sphincter Muscle: > Any of the ringlike muscles surrounding and able to contract or close a bodily passage or opening. One of the most important human sphincter muscles is the **sphincter pylori** , a thickening of the middle layer of stomach muscle around the pylorus (opening into the small intestine) that holds food in the stomach until it is thoroughly mixed with gastric juices. Other sphincters are involved in excretion of waste: the **sphincter ani externus** keeps the anal opening closed by its normal contraction, and the **sphincter urethrae** is the most important voluntary control of urination. There is also a sphincter in the eye, the **sphincter pupillae** , a ring of fibres in the iris that contracts the pupil in the presence of bright light.