Pediatricians developed their own metrics: the Stool Hardness and Transit (Shat) score and the Found and Retrieved Time (Fart) score.

From my 2005 trip to California

The Fart score – how many days it took the Lego to pass through the bowels – was between 1.1 days and three days, with an average of 1.7 days.

Using the Shat score, the researchers also found the consistency of their stools did not change. They compared Shat and Fart scores to see if looser stools caused quicker retrieval but found no correlation.

Saving this for later because given how many LEGO sets we have in the house, it seems a given Fleur is going to swallow some. Though, I have to admit my dubiousness to the study because it seems likely toddler and adult bowels might have differences such as size.