Dr Saurabh Sethi, a gastroenterologist in California, took to TikTok to share why shopping makes you poop

A Harvard-trained doctor has revealed why shopping trips are more likely to have you running for the bathroom. 

Dr Saurabh Sethi, a gastroenterologist in California, took to TikTok to share that it's not just your imagination: going shopping really does set off a signal in your bowels. 

In the video, which has over 30,000 views, Dr Sethi said: 'Let me explain. This phenomenon is known as the Mariko Aoki phenomenon, which was first described in Japan in 1985.'

'A lot of my patients have shared with me that they have also experienced the same thing.'

The term is named after a woman who wrote in a Japanese magazine that every time she wandered around in a bookstore, she had a sudden urge to use the restroom. 

Dr Sethi said that this sudden urge is called the Mariko Aoki phenomenon. The term is named after a woman who wrote in a Japanese magazine that every time she wandered around in a bookstore, she had a sudden urge to use the restroom

Some researchers theorize that the smell of coffee and books in stores like Barnes & Noble can stimulate a bowel movement

According to McGill University, several readers wrote in and said they had experienced the same thing. The magazine published a follow-up piece with the headline, 'shaking the bookstore industry.' 

While it's unclear what exactly about a Barnes & Noble or Target triggers Mariko Aoki, Dr Sethi suggested it could be due to certain spells like books or coffee.  

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The caffeine in coffee, for example, has been shown to stimulate contractions in the colon and speeds up digestion - even if you don't drink it. 

Additionally, roasted coffee contains compounds like chlorogenic acid, which triggers higher stomach acid levels, forcing the stomach to dump out its contents faster than normal. 

This could explain why walking past the coffee bar at Barnes & Noble or the Starbucks popup in Target could lead you to the bathroom.

As for books, one theory is that the smell of ink and paper has a natural laxative effect, though this hasn't been thoroughly studied. 

Other research suggests that leaning forward or being hunched over, such as while shopping for books, massages the digestive organs and leads to an easier time passing a bowel movement. 

Dr Sethi also noted that feeling relaxed – or anxious – by shopping can bring this feeling on. 

When you're feeling anxious, your gut produces higher levels of the neurotransmitter serotonin, which sends messages between nerve cells in the brain and the rest of the body.

This increased serotonin can cause colon spasms that trigger a bowel movement.

Dr Sethi said that some people 'even visit specific stores daily to make their bowels move.'

TikTok users flocked to the comments to share their own experiences.

'Happen with me every time I am shopping, a user named Nora said.

Someone else commented: 'It’s probably just from walking around for some people who aren’t active.'

'Library in college always did it to me. Regular as a clock,' a user named Terry added.

Another user said: 'Greeting card shopping. Every single time.'