Got kidney stones? Try riding roller coasters!

Getting rid of kidney stones may now be as fun as going on a roller coaster, according to scientists who found that the adventurous ride helps patients pass stones with nearly 70 per cent success rate.
"I had patients telling me that after riding a particular roller coaster at Walt Disney World, they were able to pass their kidney stone," said David Wartinger, urologist at Michigan State University in the US.
"I even had one patient say he passed three different stones after riding multiple times," Wartinger said.
He then conducted studies to assess whether the stories he was hearing from patients were true.

Using a validated, synthetic 3D model of a hollow kidney complete with three kidney stones no larger than 4 millimetres inserted into the replica, he took the model in a backpack on a roller coaster named 'Big Thunder Mountain' 20 times. His initial results verified patient reports.
"In the pilot study, sitting in the last car of the roller coaster showed about a 64 per cent passage rate, while sitting in the first few cars only had a 16 per cent success rate," Wartinger said.

The expanded study included riding the same roller coaster with multiple kidney models attached to the researchers.

They discovered even better results while sitting in the back of the coaster, with passage rate of nearly 70 per cent.
They also found that both studies showed a 100 per cent passage rate if the stones were located in the upper chamber of the kidney.
"In all, we used 174 kidney stones of varying shapes, sizes and weights to see if each model worked on the same ride and on two other roller coasters," Wartinger said.
"Big Thunder Mountain was the only one that worked. We tried Space Mountain and Aerosmith's Rock 'n' Roller Coaster and both failed," he said.

Wartinger went on to explain that these other rides are too fast and too violent with a G-force that pins the stone into the kidney and doesn't allow it to pass.
"The ideal coaster is rough and quick with some twists and turns, but no upside down or inverted movements," he said.
Lithotripsy, which breaks apart kidney stones that are too large to pass, is a common treatment for the problem. Wartinger said the procedure is usually used in cases where the kidney stone is larger than 5 millimetres.
"The problem though is lithotripsy can leave remnants in the kidney which can result in another stone," Wartinger said.

"The best way to potentially eliminate this from happening is to try going on a roller coaster after a treatment when the remnants are still small," he said.
He added that patients could even try going on a coaster once a year as maintenance, lessening the chances of future issues and minimising health care costs.
The study was published in the Journal of the American Osteopathic Association.