# Sex and digestion **URL:** \ **Category:** Factual Questions\ **Created:** [April 27, 2016, 11:56pm UTC](https://boards.straightdope.com/t/sex-and-digestion/753293 "2016-04-27T23:56:46Z")\ **Posts on this page:** 19\ **Page:** 1
**Author:** ![cjackson](https://avatars.discourse-cdn.com/v4/letter/c/a3d4f5/32.png) [@cjackson](https://boards.straightdope.com/u/cjackson)\ **Post date:** [April 27, 2016, 11:56pm UTC](https://boards.straightdope.com/t/sex-and-digestion/753293/1 "2016-04-27T23:56:46Z")
What affect does intercourse have on the digestive system of humans? I’ve heard that that the stomach blushes. So do people who are deeply in love having sex cause any changes in digestion? What about sex after a large meal? ---
**Author:** ![pojimba](https://avatars.discourse-cdn.com/v4/letter/p/bcef8e/32.png) [@pojimba](https://boards.straightdope.com/u/pojimba)\ **Post date:** [April 28, 2016, 12:04am UTC](https://boards.straightdope.com/t/sex-and-digestion/753293/2 "2016-04-28T00:04:13Z")
What about people who aren’t deeply in love? Hmm? ---
**Author:** ![spamforbrains](https://avatars.discourse-cdn.com/v4/letter/s/e274bd/32.png) [@spamforbrains](https://boards.straightdope.com/u/spamforbrains)\ **Post date:** [April 28, 2016, 12:50am UTC](https://boards.straightdope.com/t/sex-and-digestion/753293/3 "2016-04-28T00:50:58Z")
> [@](#): > > I’ve heard that that the stomach blushes um, what? ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [April 28, 2016, 2:14am UTC](https://boards.straightdope.com/t/sex-and-digestion/753293/4 "2016-04-28T02:14:53Z")
Huh. [It’s true](http://www.wisegeek.com/does-your-stomach-lining-really-turn-red-when-you-blush.htm). > [@](#): > > Your stomach lining turns red when you blush, a response that is the result of the sympathetic nervous system causing increased blood flow throughout the body. During periods of embarrassment, the body releases adrenaline, a hormone that prepares the body for stressful situations. Adrenaline also makes the blood vessels dilate in order to improve blood flow and oxygen delivery in case the body has to suddenly flee a dangerous situation. The veins in the face, as well as in the stomach lining and throughout the rest of the body, then have more blood than normal flowing through them, and they appear red. What this has to do with sex is beyond me. Stomach Blushes wouldn’t make a bad band name, though. They could do a double bill with the Gin Blossoms. ---
**Author:** ![AHunter3](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ahunter3/32/368_2.png) [@AHunter3](https://boards.straightdope.com/u/AHunter3)\ **Post date:** [April 28, 2016, 2:28am UTC](https://boards.straightdope.com/t/sex-and-digestion/753293/5 "2016-04-28T02:28:21Z")
When people fall in love, they rather notoriously have changes in appetite for food. But I think that has more to do with biochemicals affecting the brain than blood flow to the intestines. ---
**Author:** ![spamforbrains](https://avatars.discourse-cdn.com/v4/letter/s/e274bd/32.png) [@spamforbrains](https://boards.straightdope.com/u/spamforbrains)\ **Post date:** [April 28, 2016, 2:32am UTC](https://boards.straightdope.com/t/sex-and-digestion/753293/6 "2016-04-28T02:32:48Z")
> [@](#): > > What this has to do with sex is beyond me. one would hope a couple in love is neither embarrassed by or experiencing a severe flight or fight response during their sexual encounters. as to the original question about digestion and sex, I quote Dan Savage: “Fuck first” ---
**Author:** ![UDS](https://avatars.discourse-cdn.com/v4/letter/u/ecae2f/32.png) [@UDS](https://boards.straightdope.com/u/UDS)\ **Post date:** [April 28, 2016, 2:37am UTC](https://boards.straightdope.com/t/sex-and-digestion/753293/7 "2016-04-28T02:37:53Z")
I suppose increased blood flow to the stomach might improve the efficiency of digestion in the stomach - the rate of secretion of enzymes and acid might increase, which would make for quicker breakdown of food in the stomach. But surely the effect would be transient? Blushes fade very quickly. And if I recall correctly the stomach doesn’t absorb any food; it just breaks it down so that it can be more easily absorbed when it passes into the lower intestine. So the effects on absorbtion of food would be pretty minor, I would think. Other things apart from orgasm cause you to blush. Do you find that acute embarrassment improves your digestion? No? Well, then, I wouldn’t expect too much improvement from orgasm either. ---
**Author:** ![spamforbrains](https://avatars.discourse-cdn.com/v4/letter/s/e274bd/32.png) [@spamforbrains](https://boards.straightdope.com/u/spamforbrains)\ **Post date:** [April 28, 2016, 2:52am UTC](https://boards.straightdope.com/t/sex-and-digestion/753293/8 "2016-04-28T02:52:26Z")
why would sex and orgasms cause you to blush? ---
**Author:** ![Spiderman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/spiderman/32/230_2.png) [@Spiderman](https://boards.straightdope.com/u/Spiderman)\ **Post date:** [April 28, 2016, 2:59am UTC](https://boards.straightdope.com/t/sex-and-digestion/753293/9 "2016-04-28T02:59:11Z")
They’ve debunked [swimming after eating](http://www.snopes.com/oldwives/hourwait.asp) but I don’t think many kids have sex after eating. :rolleyes: ---
**Author:** ![UDS](https://avatars.discourse-cdn.com/v4/letter/u/ecae2f/32.png) [@UDS](https://boards.straightdope.com/u/UDS)\ **Post date:** [April 28, 2016, 3:01am UTC](https://boards.straightdope.com/t/sex-and-digestion/753293/10 "2016-04-28T03:01:26Z")
> [@spamforbrains](#): > > why would sex and orgasms cause you to blush? You need to, ahem, see a wider variety of people. About two-thirds of women, and about a quarter of men, become signficantly flushed when they orgasm. ---
**Author:** ![UDS](https://avatars.discourse-cdn.com/v4/letter/u/ecae2f/32.png) [@UDS](https://boards.straightdope.com/u/UDS)\ **Post date:** [April 28, 2016, 3:02am UTC](https://boards.straightdope.com/t/sex-and-digestion/753293/11 "2016-04-28T03:02:44Z")
> [@Spiderman](#): > > They’ve debunked [swimming after eating](http://www.snopes.com/oldwives/hourwait.asp) but I don’t think many kids have sex after eating. :rolleyes: Surely that’s the whole point of taking someone out to dinner? ---
**Author:** ![Spiderman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/spiderman/32/230_2.png) [@Spiderman](https://boards.straightdope.com/u/Spiderman)\ **Post date:** [April 28, 2016, 3:22am UTC](https://boards.straightdope.com/t/sex-and-digestion/753293/12 "2016-04-28T03:22:36Z")
> [@UDS](#): > > Surely that’s the whole point of taking someone out to dinner? I’ll [drink](https://www.youtube.com/watch?v=Z2BSEZFuWdY&t=0m6s) to that. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [April 28, 2016, 3:24am UTC](https://boards.straightdope.com/t/sex-and-digestion/753293/13 "2016-04-28T03:24:51Z")
> [@UDS](#): > > You need to, ahem, see a wider variety of people. About two-thirds of women, and about a quarter of men, become signficantly flushed when they orgasm. Being flushed after orgasm is not physiologically related to blushing. ---
**Author:** ![UDS](https://avatars.discourse-cdn.com/v4/letter/u/ecae2f/32.png) [@UDS](https://boards.straightdope.com/u/UDS)\ **Post date:** [April 28, 2016, 3:36am UTC](https://boards.straightdope.com/t/sex-and-digestion/753293/14 "2016-04-28T03:36:01Z")
> [@Exapno\_Mapcase](#): > > Being flushed after orgasm is not physiologically related to blushing. But it’s what cjackson is talking about in the OP. Besides, [Wikipedia](https://en.wikipedia.org/wiki/Flushing_(physiology))tells me that, although “flushing” and “blushing” are generally distinguished, there is a a “close physiological relation between them”. And who am I to argue with Wikipedia? ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [April 28, 2016, 3:48pm UTC](https://boards.straightdope.com/t/sex-and-digestion/753293/15 "2016-04-28T15:48:23Z")
> [@UDS](#): > > But it’s what cjackson is talking about in the OP. Is it? I can’t figure out how you know that. > [@](#): > > Besides, [Wikipedia](https://en.wikipedia.org/wiki/Flushing_(physiology))tells me that, although “flushing” and “blushing” are generally distinguished, there is a a “close physiological relation between them”. And who am I to argue with Wikipedia? Yes, both involve increased blood flow. The important distinction is that orgasmic flushing is not, AFAIK, caused by adrenaline. ---
**Author:** ![Boyo\_Jim](https://avatars.discourse-cdn.com/v4/letter/b/87869e/32.png) [@Boyo\_Jim](https://boards.straightdope.com/u/Boyo_Jim)\ **Post date:** [April 28, 2016, 4:21pm UTC](https://boards.straightdope.com/t/sex-and-digestion/753293/16 "2016-04-28T16:21:04Z")
> [@spamforbrains](#): > > why would sex and orgasms cause you to blush? Pity fucks? ---
**Author:** ![UDS](https://avatars.discourse-cdn.com/v4/letter/u/ecae2f/32.png) [@UDS](https://boards.straightdope.com/u/UDS)\ **Post date:** [April 29, 2016, 1:21am UTC](https://boards.straightdope.com/t/sex-and-digestion/753293/17 "2016-04-29T01:21:26Z")
> [@Exapno\_Mapcase](#): > > Is it? I can’t figure out how you know that. Well, my suspicions were first aroused when I read the very start of the OP: > [@cjackson](#): > > What affect does intercourse have on the digestive system of humans? I’ve heard that that the stomach blushes . . . I though “Oh, he’s talking about the sex flush”. I still think that. Do you think he could possibly be talking about something else and, if so, what? > [@Exapno\_Mapcase](#): > > Yes, both involve increased blood flow. The important distinction is that orgasmic flushing is not, AFAIK, caused by adrenaline. But it’s the increased blood flow, I suggest in post #7, which might possibly have a effect on the efficiency of digestion. (Though I doubt that it does have that effect to any meaningful extent.) ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [April 29, 2016, 2:28am UTC](https://boards.straightdope.com/t/sex-and-digestion/753293/18 "2016-04-29T02:28:27Z")
> [@UDS](#): > > Well, my suspicions were first aroused when I read the very start of the OP: > I though “Oh, he’s talking about the sex flush”. I still think that. Do you think he could possibly be talking about something else and, if so, what? Since stomach blushes are a real thing and sexual flushing is far more evident almost everywhere they exist than the stomach, I think he could be talking about, you know, stomach blushes. But I’m not going to expend an ounce more effort unless the OP comes back to explain. ---
**Author:** ![spamforbrains](https://avatars.discourse-cdn.com/v4/letter/s/e274bd/32.png) [@spamforbrains](https://boards.straightdope.com/u/spamforbrains)\ **Post date:** [April 29, 2016, 3:04am UTC](https://boards.straightdope.com/t/sex-and-digestion/753293/19 "2016-04-29T03:04:23Z")
> [@](#): > > Being flushed after orgasm is not physiologically related to blushing. exactly. Blushing is related to being stressed, which is not good for digestion. Just offhand, I would expect being relaxed after sex to improve digestion. However, I doubt anyone has actually studied this. Because, well, why?