While we often feel great post-poop, other times, there’s an energy slump that happens—and not just to you. Yes, there’s actually a medical explanation for the phenomenon. Here’s the deal.
What can cause you to feel tired after you poop?
A lot of it comes down to your vagal nerves (aka vagus nerve), which are the main nerves of your parasympathetic nervous system. These nerves control a range of functions in your body, including your digestion, heart rate, and immune system.
“Straining really hard during a bowel movement can activate the vagus,” explains Ellen M. Stein, MD, associate professor of medicine in the Division of Gastroenterology and Hepatology at Rutgers Robert Wood Johnson Medical School. For some people, heart rate slows and blood pressure lowers when the vagus nerve is activated, leading to something called a vasovagal reflex, Dr. Stein says.
“If you’re straining or pushing hard, your stomach muscles are contracting and that will decrease blood flow into the vagus nerve,” says Rudolph Bedford, MD, a gastroenterologist at Providence Saint John’s Health Center in Santa Monica, California. “That can make you feel dizzy when you get up after a bowel movement, or tired. Some people will even faint or lose consciousness if they’re straining enough.”
“Some people will even faint or lose consciousness if they’re straining enough.” —Rudolph Bedford, MD
Also worth noting: If you hold your breath when you push to poop, it can cause you to feel weak afterward, Dr. Stein says.
What does it mean if you feel tired after you poop?
On one level, it’s possible to feel exhausted after you poop simply because you’re constipated and are working hard to go, Dr. Bedford says. “You should try to keep your bowel movements soft so you’re not straining,” he suggests.
But the phenomenon can also be a sign that something else is going on with your health. “Some patients have underlying heart problems and now many patients have post-COVID syndromes or post-viral syndromes like POTS (postural orthostatic and tachycardia syndrome),” Dr. Stein says. “These conditions make their heart and circulatory system even more sensitive to these vasovagal reflexes.”
How concerning is this?
It depends. If you notice here and there that you feel tired after you poop but feel otherwise okay, Dr. Bedford says you’re probably fine to just mention it to your doctor at your next physical.
But if this is a regular thing for you, Dr. Bedford it’s a good idea to proactively reach out to your doctor to see what could be going on. “You need to not only have your blood pressure and heart rate checked, but you need some blood work done,” he says. You could be dealing with an underlying health condition you’re not aware of or may be struggling with pelvic floor issues, Dr. Stein says.
How to prevent this from happening
Since a softer stool means you’ll be less likely to strain on the toilet, Dr. Bedford recommends that you focus on adding more fruits, vegetables, and water to your diet.
You can also try adjusting your bathroom habits. “Sometimes getting your feet up on a Squatty Potty changes the angles and eases the flow,” Dr. Stein says. Getting enough sleep can also help, she says.
Also make sure you’re using proper pooping form: “Pushing harder and holding your breath are likely triggers, so gently activating the right muscles and not forgetting to breathe are really helpful,” Dr. Stein says.
But, again, if this is something you’re dealing with regularly, it’s important to flag it for your doctor. They should be able to take things from there.
