[Functional disorders of the lower urinary tract in children].

Functional disorders of the lower urinary tract as well as vesicoureteral reflux involved in the disease complex of urinary tract infection/permanent renal parenchymal damage can be considered predisposing or risk factors. Two main forms can be distinguished, i.e., unstable bladder and dysfunctional voiding, while transitional forms between the two exist. Functional disorders of the lower urinary tract obstruct spontaneous resolution of vesicoureteral reflux. They are found in about 50% of cases in all children with urinary tract infection and are associated with an increased risk of developing renal parenchymal scars. They are observed during the newborn period up to school age. In the first few months of life, particularly boys with bilateral high-grade reflux and congenital renal parenchymal damage are affected. At later ages girls are also affected, but in this age group bladder instability predominates. Incontinence as the leading clinical symptom appears in approximately 70% of all cases and is closely correlated with chronic constipation. Imaging procedures in addition to urodynamic methods are of decisive importance for diagnosis and treatment, but noninvasive approaches such as sonography should be given preference.