What's the Connection Between Bowel Movements and Erections?

Key Points

• Some men have reported getting erections while straining to force bowel movements.
• The parasympathetic nervous system is responsible for both processes, which may ultimately be the cause.
• Pelvic floor dysfunction can make it even more difficult to poop, which could further exacerbate the relationship between the two.

Plenty of things can cause a man to get hard, but getting a boner during a bowel movement is one of the more unexpected. How common is it to get hard while pooping? Let's take a look at the link between a hard-on and bowel movements.

Why do I get hard while pooping?

Embarrassed men have reluctantly asked functional gastroenterologist Sameer Islam, M.D., a gastroenterologist in Lubbock, Texas, "Why is it that I get a boner while pooping?"

Typically, these men experienced the erection when they were straining on the toilet, or they may have noticed it after an especially large bowel movement.

"The same area where you have a bowel movement is also the same area where you have the male [sexual] organs," Islam said. "Sometimes the pressure of whenever you have a bowel movement can stimulate the prostate gland and also the male genitalia. That pressure sensation that's there can cause that [erectile] response to occur."

Activation of the parasympathetic nervous system results in defecation as well as erection, which may explain the connection between bowel movements and erections, said Amy Pearlman, M.D., a men's health specialist and co-founder of Prime Institute in Fort Lauderdale, Florida.

"During a bowel movement, and particularly during a large or difficult bowel movement, increased pressure caused by the body pushing to evacuate itself may result in increased blood flow to the penis," Pearlman said.

The pudendal nerve gives sensation to the penis, the skin around the anus and the anal canal.

"For this reason, the sensation of a bowel movement can also lead to sexual stimulation," Pearlman said.

Recommended

• Kegels and Pelvic Floor Exercises: Myths and Misconceptions: Minimal effort can reap major benefits with these easy exercises—if you know what you're doing.
• What Is the Pelvic Floor and Why Does it Matter?: Exercising your pelvic floor now will save you from serious issues later.
• Strengthen Your Pelvic Floor to Improve Your Sex Life: Exercise is great for your health, but are you missing key pelvic floor exercises in your routine?

Having an erection during a bowel movement is not common, but it's also not rare, Islam said. People shouldn't freak out thinking it's not normal; it is normal.

If the erection does not go down after you finish pooping or if you're only having an erection while sitting on the toilet, that is not normal.

"When it comes to bowel habits, if you have blood or pain, that's also not normal," Islam said. "Typically, if it just doesn't go away after you have a bowel movement, that would be a time to seek help from a medical professional who can see what's going on and make sure you don't have anything else that's causing that issue."

What's the link between pelvic floor dysfunction and constipation?

Pelvic floor dysfunction occurs when there is difficulty relaxing and coordinating the pelvic muscles. This may be due to damage to or weakening of the pelvic floor and can result in problems with bowel movements, urination and sexual activity.

The analogy Islam uses is that a pelvic floor problem is like squeezing toothpaste with the cap on the tube.

"No matter how much you squeeze, you're still going to have that cap on," he said. "It's the exact same thing in the pelvic floor area in the rectum. Your rectum is tight. You are literally anally retentive. You cannot move anything out. And so, whenever you try to have a bowel movement, that pressure can also stimulate the male genitalia as well and cause the symptoms and the response to that."

Dysfunction in the pelvic floor muscles can result in constipation with an increased need to strain to defecate, requiring increased pressure during bowel movements. This may increase blood flow to the penis, Pearlman said.

Constipation and pelvic floor dysfunction can also lead to penile pain for men.

"I've seen this penile and urethral pain lead to extensive evaluations by urologists, including cystoscopy and treatment for urinary tract infections," Pearlman said. "It's really important to assess bowel habits in these men as well as evaluate and treat for pelvic floor dysfunction."

Pelvic floor dysfunction is often treated by a physical therapist who specializes in pelvic health.

How can you promote regular bowel movements and manage constipation?

Regular bowel movements are important to reducing the risk of uncomfortable symptoms such as bloating and constipation that can influence libido and how you feel overall during sexual activity, said Michelle Pearlman, M.D., a gastroenterologist and co-founder of Prime Institute in Fort Lauderdale, Florida.

"Whole food, plant-based nutrition plans that contain 20 to 25 grams of fiber per day are recommended for most people," Michelle Pearlman said. "Fiber is essential to help promote a diverse microbiome, which is important to optimize the gut-brain axis and, ultimately, overall health."

Beyond pelvic floor problems, the relationship between bowel movements and erections is such an underreported and understudied phenomenon that Islam is not aware of other underlying conditions that can contribute to it.

There are even instances where what men are experiencing on the toilet isn't actually an erection.

Laurence Levine, M.D., a professor of urology at Rush University Medical Center in Chicago, sees a lot of men with erectile dysfunction (ED), or the inability to achieve and maintain an erection firm enough for sexual activity.

"Some men with ED have told me, 'Jeez, you know, when I sit on a toilet, sometimes I push, and I can see that I get a partial erection.' And, of course, that may be because, when they push, they're increasing venous flow down in the deep pelvis and that may result in some type of passive flow of blood into the penis. Is it an erection? No. It's just some tumescence that occurs as a result of straining at stool."

Having an erection during a bowel movement may not require medical attention, Amy Pearlman said—but similar issues can.

"Chronic constipation can cause issues like hemorrhoids, so it is important to manage chronic constipation with hydration, good nutrition, exercise, over-the-counter medications, and evaluation and treatment by a healthcare professional when these interventions are ineffective."

The bottom line

From constipation to pelvic floor dysfunction, there are several different reasons why you may get a boner when you're having a bowel movement. If you experience chronic constipation, pain or sexual dysfunction, such as ED, speak to your doctor.

Treatment is available.