# Anatomy: why is it hard for a man to pee shortly after ejaculation? **URL:** \ **Category:** Factual Questions\ **Created:** [September 9, 2013, 2:56am UTC](https://boards.straightdope.com/t/anatomy-why-is-it-hard-for-a-man-to-pee-shortly-after-ejaculation/668385 "2013-09-09T02:56:37Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [September 9, 2013, 2:56am UTC](https://boards.straightdope.com/t/anatomy-why-is-it-hard-for-a-man-to-pee-shortly-after-ejaculation/668385/1 "2013-09-09T02:56:37Z")
Subject line contains the basic question: shortly after orgasm/ejaculation, it’s usually a few minutes before I can pass urine. What’s happening to produce this phenomenon? ---
**Author:** ![yoyodyne](https://avatars.discourse-cdn.com/v4/letter/y/a9a28c/32.png) [@yoyodyne](https://boards.straightdope.com/u/yoyodyne)\ **Post date:** [September 9, 2013, 3:17am UTC](https://boards.straightdope.com/t/anatomy-why-is-it-hard-for-a-man-to-pee-shortly-after-ejaculation/668385/2 "2013-09-09T03:17:58Z")
The bladder neck muscles autonomically contract during ejaculation to prevent semen from going into the bladder instead of out the urethra. It just take a little while to relax. ---
**Author:** ![robert\_columbia](https://avatars.discourse-cdn.com/v4/letter/r/e79b87/32.png) [@robert\_columbia](https://boards.straightdope.com/u/robert_columbia)\ **Post date:** [September 9, 2013, 5:15am UTC](https://boards.straightdope.com/t/anatomy-why-is-it-hard-for-a-man-to-pee-shortly-after-ejaculation/668385/3 "2013-09-09T05:15:56Z")
\ You said “hard”. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [September 9, 2013, 11:12am UTC](https://boards.straightdope.com/t/anatomy-why-is-it-hard-for-a-man-to-pee-shortly-after-ejaculation/668385/4 "2013-09-09T11:12:41Z")
> [@yoyodyne](#): > > The bladder neck muscles autonomically contract during ejaculation to prevent semen from going into the bladder instead of out the urethra. It just take a little while to relax. A useful adapation, I suppose, to ensure that those precious bodily fluids go where they’re supposed to. But why do the muscles remain contracted for some time post-climax? ---
**Author:** ![ombre12](https://avatars.discourse-cdn.com/v4/letter/o/d26b3c/32.png) [@ombre12](https://boards.straightdope.com/u/ombre12)\ **Post date:** [September 9, 2013, 11:19am UTC](https://boards.straightdope.com/t/anatomy-why-is-it-hard-for-a-man-to-pee-shortly-after-ejaculation/668385/5 "2013-09-09T11:19:36Z")
> [@yoyodyne](#): > > The bladder neck muscles autonomically contract during ejaculation to prevent semen from going into the bladder instead of out the urethra. It just take a little while to relax. Sounds right. Does anything similar happen to a woman after orgasm? I know there is no semen to justify it, but aren’t male and female muscles around that area similar? ---
**Author:** ![DrFidelius](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/drfidelius/32/3447_2.png) [@DrFidelius](https://boards.straightdope.com/u/DrFidelius)\ **Post date:** [September 9, 2013, 11:30am UTC](https://boards.straightdope.com/t/anatomy-why-is-it-hard-for-a-man-to-pee-shortly-after-ejaculation/668385/6 "2013-09-09T11:30:13Z")
> [@Machine\_Elf](#): > > A useful adapation, I suppose, to ensure that those precious bodily fluids go where they’re supposed to. But why do the muscles remain contracted for some time post-climax? Why not? It’s not as if anyone ever died from that. ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [September 9, 2013, 11:50am UTC](https://boards.straightdope.com/t/anatomy-why-is-it-hard-for-a-man-to-pee-shortly-after-ejaculation/668385/7 "2013-09-09T11:50:32Z")
> [@DrFidelius](#): > > Why not? It’s not as if anyone ever died from that. But if the semen doesn’t go ‘out’ it can’t make babies. Path of least resistance and all that. ---
**Author:** ![DrFidelius](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/drfidelius/32/3447_2.png) [@DrFidelius](https://boards.straightdope.com/u/DrFidelius)\ **Post date:** [September 9, 2013, 12:18pm UTC](https://boards.straightdope.com/t/anatomy-why-is-it-hard-for-a-man-to-pee-shortly-after-ejaculation/668385/8 "2013-09-09T12:18:05Z")
> [@Joey\_P](#): > > But if the semen doesn’t go ‘out’ it can’t make babies. Path of least resistance and all that. Thus, post-ejaculation urine clamp is selectively neutral, as it occurs after the male has bred. Now, if PEUC causes men to die before their children reach breeding age themselves, it might be selected against. But if, as I said, no one has ever died for not being able to take a leak for a few minutes after ejaculation, it cannot be selected against. ---
**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\ **Post date:** [September 9, 2013, 12:21pm UTC](https://boards.straightdope.com/t/anatomy-why-is-it-hard-for-a-man-to-pee-shortly-after-ejaculation/668385/9 "2013-09-09T12:21:32Z")
> [@DrFidelius](#): > > Thus, post-ejaculation urine clamp is selectively neutral, as it occurs after the male has bred. “Bred”? You’re a veterinarian, right? ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [September 9, 2013, 1:01pm UTC](https://boards.straightdope.com/t/anatomy-why-is-it-hard-for-a-man-to-pee-shortly-after-ejaculation/668385/10 "2013-09-09T13:01:40Z")
> [@DrFidelius](#): > > Thus, post-ejaculation urine clamp is selectively neutral… This is what I was wondering - does this phenomenon serve an evolutionarily useful purpose, or is it just a harmless artifact of the way the reproductive system happened to evolve? ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [September 9, 2013, 1:27pm UTC](https://boards.straightdope.com/t/anatomy-why-is-it-hard-for-a-man-to-pee-shortly-after-ejaculation/668385/11 "2013-09-09T13:27:34Z")
Before this gets up to full speed, did **DrFidelius** just invent the term “post-ejaculation urine clamp?” It sounds doctory, and even has an abbreviation. Even if (because?) **DrFidelius** is a vet. ETA: I need to know who to give credit to the next time the situation arises (npi) and I tell my wife why I’m getting up (npi). I’m conscientious that way. ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [September 9, 2013, 1:40pm UTC](https://boards.straightdope.com/t/anatomy-why-is-it-hard-for-a-man-to-pee-shortly-after-ejaculation/668385/12 "2013-09-09T13:40:04Z")
> [@DrFidelius](#): > > Thus, post-ejaculation urine clamp is selectively neutral, as it occurs after the male has bred. Now, if PEUC causes men to die before their children reach breeding age themselves, it might be selected against. But if, as I said, no one has ever died for not being able to take a leak for a few minutes after ejaculation, it cannot be selected against. What happens after ejaculation is kinda irrelevant. ---
**Author:** ![DrFidelius](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/drfidelius/32/3447_2.png) [@DrFidelius](https://boards.straightdope.com/u/DrFidelius)\ **Post date:** [September 9, 2013, 1:42pm UTC](https://boards.straightdope.com/t/anatomy-why-is-it-hard-for-a-man-to-pee-shortly-after-ejaculation/668385/13 "2013-09-09T13:42:36Z")
> [@Leo\_Bloom](#): > > Before this gets up to full speed, did **DrFidelius** just invent the term “post-ejaculation urine clamp?” It sounds doctory, and even has an abbreviation. > > Even if (because?) **DrFidelius** is a vet. > ETA: I need to know who to give credit to the next time the situation arises (npi) and I tell my wife why I’m getting up (npi). I’m conscientious that way. As far as I know, I did just make that up on the fly. Come to think of it, it sounds like one of those uncomfortable devices for sale at Ilsa’s Leather Boutique. ---
**Author:** ![Thudlow\_Boink](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thudlow_boink/32/320_2.png) [@Thudlow\_Boink](https://boards.straightdope.com/u/Thudlow_Boink)\ **Post date:** [September 9, 2013, 1:54pm UTC](https://boards.straightdope.com/t/anatomy-why-is-it-hard-for-a-man-to-pee-shortly-after-ejaculation/668385/14 "2013-09-09T13:54:12Z")
> [@DrFidelius](#): > > As far as I know, I did just make that up on the fly. Is _that_ where the urine clamp is? ---
**Author:** ![yoyodyne](https://avatars.discourse-cdn.com/v4/letter/y/a9a28c/32.png) [@yoyodyne](https://boards.straightdope.com/u/yoyodyne)\ **Post date:** [September 9, 2013, 2:32pm UTC](https://boards.straightdope.com/t/anatomy-why-is-it-hard-for-a-man-to-pee-shortly-after-ejaculation/668385/15 "2013-09-09T14:32:13Z")
> [@Machine\_Elf](#): > > A useful adapation, I suppose, to ensure that those precious bodily fluids go where they’re supposed to. But why do the muscles remain contracted for some time post-climax? For “why” in the evolutionary sense, why not? For “why” in the mechanics sense, you’d have to ask a neuroscientist. It’s a spinal reflex, I suspect it would have something to do with neurotransmitter re-uptake time. > [@ombre12](#): > > Sounds right. Does anything similar happen to a woman after orgasm? I know there is no semen to justify it, but aren’t male and female muscles around that area similar? During my online research, I have observed a number of women having presumably real orgasms that result in the involuntary emission of what is obviously urine. Based on that I would assume the answer is no. ---
**Author:** ![simster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/simster/32/1047_2.png) [@simster](https://boards.straightdope.com/u/simster)\ **Post date:** [September 9, 2013, 3:28pm UTC](https://boards.straightdope.com/t/anatomy-why-is-it-hard-for-a-man-to-pee-shortly-after-ejaculation/668385/16 "2013-09-09T15:28:05Z")
IIRC, the real premise was to prevent the flow of Urine once excited, as urine can kill sperm (due to acidity?) - thats the purpose of ‘pre-ejaculate’ (clean the pipes), etc. So, it follows that keeping it clamped afterwards is just an extension of that - ---
**Author:** ![lieu](https://avatars.discourse-cdn.com/v4/letter/l/c2a13f/32.png) [@lieu](https://boards.straightdope.com/u/lieu)\ **Post date:** [September 9, 2013, 3:32pm UTC](https://boards.straightdope.com/t/anatomy-why-is-it-hard-for-a-man-to-pee-shortly-after-ejaculation/668385/17 "2013-09-09T15:32:28Z")
> [@DrFidelius](#): > > As far as I know, I did just make that up on the fly. Come to think of it, it sounds like one of those uncomfortable devices for sale at Ilsa’s Leather Boutique. I was reminded of a capo. ---
**Author:** ![gracer](https://avatars.discourse-cdn.com/v4/letter/g/8e7dd6/32.png) [@gracer](https://boards.straightdope.com/u/gracer)\ **Post date:** [September 9, 2013, 3:33pm UTC](https://boards.straightdope.com/t/anatomy-why-is-it-hard-for-a-man-to-pee-shortly-after-ejaculation/668385/18 "2013-09-09T15:33:16Z")
RE women: For me, and I hear the same thing from friends, I can pee right after but I can’t always walk properly. So there is some muscular funniness, but not in the bladder/urethra department. ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [September 9, 2013, 3:39pm UTC](https://boards.straightdope.com/t/anatomy-why-is-it-hard-for-a-man-to-pee-shortly-after-ejaculation/668385/19 "2013-09-09T15:39:31Z")
> [@gracer](#): > > … I can’t always walk properly. … Huh? 😕 ---
**Author:** ![dracoi](https://avatars.discourse-cdn.com/v4/letter/d/90db22/32.png) [@dracoi](https://boards.straightdope.com/u/dracoi)\ **Post date:** [September 9, 2013, 4:27pm UTC](https://boards.straightdope.com/t/anatomy-why-is-it-hard-for-a-man-to-pee-shortly-after-ejaculation/668385/20 "2013-09-09T16:27:05Z")
I thought it was hard to pee after ejaculation because you were asleep by then. 🙂 [Next page](https://boards.straightdope.com/t/anatomy-why-is-it-hard-for-a-man-to-pee-shortly-after-ejaculation/668385.md?page=2)