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.
Pain â Pain is the most common symptom when passing a kidney stone. Most commonly, pain only occurs with obstruction, in which the urine cannot pass freely from the kidney to the bladder. Pain can range from a mild and barely noticeable ache to discomfort that is so intense it requires treatment in the hospital.