Stenosis is the anatomic narrowing of the lumen of the ureter.
A stricture is commonly thought of as an 'obstruction' related to development. Many times this anomaly is not diagnosed in infancy and, unless it is severe, it can remain undiagnosed. This anomaly is more common in males. The portion of the ureter immediately preceding the stenotic or strictured area enlarges in order to accommodate the decreased flow of urine into the bladder. There are three areas of the ureter that are most prone to become stenotic.