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Six Scientists Swallowed Lego Heads To Establish How Long It Takes To Poop Out

What goes in must come out.


Rachael Funnell


Rachael Funnell

Writer & Senior Digital Producer

Rachael is a writer and digital content producer at IFLScience with a Zoology degree from the University of Southampton, UK, and a nose for novelty animal stories.

Writer & Senior Digital Producer

child swallowed lego

The researchers were brave. The Lego heads were even braver. Image credit: Ekaterina_Minaeva /

Pre-SHAT score. Post-SHAT score. FART score. You’d be familiar with these tests had you read Volume 55 of the Journal Of Paediatrics And Child Health. Why? Because in 2018, a group of researchers decided to find out how long it takes to poop Lego.

Six pediatric health care professionals took on the challenge in a study titled “Everything is awesome: Don't forget the Lego”. The brave volunteers had to pass three exclusion criteria to participate:

  • Previous gastrointestinal surgery
  • Inability to ingest foreign objects
  • Aversion to searching through fecal matter

Once they had their crack team of feces filterers, the researchers established participants’ normal bowel habits using the Stool Hardness and Transit score. Also known as the SHAT score. This was then compared against their SHAT score after they’d ingested the Lego head, giving them pre-SHAT and post-SHAT data points for analysis.

Lego heads swallowed, the race was on. Participants were required to search through their fecal matter in the hopes that one day they’d find that little yellow head smiling up at them. The time that took became the Found and Retrieved Time (FART) score.

In case these details have you staring incredulously at your phone, the trip down the human esophagus was necessary because, as any parent will tell you, kids love shoving things in their mouths. From six months of age to three years, children experience an early oral development phase that sees them exploring the world with their face holes. A crucial part in developing our senses, sure, but it also comes with the side effect of swallowed foreign objects.

Parents are understandably concerned when they believe their child to have swallowed something they shouldn’t have. Magnetic ball bearings are a particularly dangerous culprit, capable of perforating the bowel if they start to move. And who could forget the fable of the Astrophysicist who got magnets stuck up his nose trying to create a device that would stop people touching their faces during the COVID-19 pandemic?

how long to poop out a lego
The Lego heads went where countless Lego heads have gone before: on a trip down the human digestive tract. Image credit: G Leo, © 2018 Paediatrics and Child Health Division (The Royal Australasian College of Physicians)

Surgery may be required in the case of objects that are potentially dangerous, but when it comes to more innocuous things like a piece of Lego, medical intervention may be unnecessary. Establishing this requires gaining a scientific understanding of how long it takes for Lego to pass through the human digestive tract, welcoming to the world the SHAT and FART scores.

It took an average of 1.71 days for the Lego head to exit the body, with a varied FART score between 1.14 and 3.04 days. The researchers also note that “females may be more accomplished at searching through their stools than males”, adding this “could not be statistically validated”. Presumably, this is referring to the fact that one male volunteer never found their Lego head. Whelp.

While the researchers note that it’s possible the transit time in a child’s comparatively shorter bowel may be fundamentally different from an adult, there’s not much in the literature to suggest it would be. If anything, a kid is likely to see their blocky pal much sooner than an adult.

The findings are intended to be a reassurance for worried parents that lost Legos will probably pass through a child’s digestive system unnoticed, as well as saving them the dirty job of painstakingly picking through poo for MIA Legos. 


"If an experienced clinician with a PhD is unable to adequately find objects in their own stool, it seems clear that we should not be expecting parents to do so,” they concluded, adding that the approach has some limitations, but also some perks.

“The population studied could not be blinded to the study outcomes as we felt it was unfair on the authors' partners or colleagues to search through their waste products. We also recognise that the Stool Hardness and Transit score is not a perfect surrogate for underlying bowel pattern, but the fact that participants can SHAT themselves without specialist knowledge makes it an inexpensive tool.”

The study is published in the Journal of Paediatrics and Child Health.


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