Platyhelminthes are also known as flatworms because they are worms with a flat body. This is the main external morphological feature that differentiates them from nematodes (roundworms).
Even though 85 percent of kidney stones are small enough to pass during urination, fewer than 50 percent of patients chose this option. A person with a normal-size ureter can usually pass a kidney stone with a diameter less than 5 mm (about 3/16 of an inch) without significant pain or risk of kidney damage.
Most kidney stones that pass on their own do so by 40 days. Medications called antispasmodics may be prescribed to help a stone pass. They relax the ureters, which can increase the likelihood of passing a stone and speed up passage by 5 to 7 days, according to an article in the December 2011 issue of the âAmerican Family Physician.â