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.
A kidney stone may be as small as a grain of sand or as large as a pearl, and some are as big as golf balls. They may be smooth, irregular in shape, or jagged, and are usually yellow or brown in color. kidney stone may be as small as a grain of sand or as large as a pearl, and some are as big as golf balls. They may be smooth, irregular in shape, or jagged, and are usually yellow or brown in color.