To describe the clinical presentation and urodynamic findings in detrusor underactivity (DU) patients and investigate the association between DU and straining related complications such as pelvic organ prolapse (POP), inguinal hernia, and hemorrhoids.

We retrospectively reviewed all consecutive patients who underwent urodynamic studies (UDS) from 2012 to 2023, divided into two groups: those with evidence of DU (n = 573), and control subjects with normal voiding parameters (n = 522). Exclusion criteria were patients who lacked sufficient data, those with obstructive voiding parameters, and those who had received intravesical botulinum toxin injections within the previous nine months. Demographic information, clinical presentation, straining related complications, and UDS findings were compared between the two groups using univariate statistical analysis.

The male DU group had a statistically significant higher prevalence of spinal disease and previous cerebrovascular accidents, while the female DU group had a statistically significant higher prevalence of spinal disease, multiple sclerosis, diabetes, previous colorectal surgery, previous transabdominal gynecological surgery, POP surgery, and recurrent UTIs. Female DU patients had a higher prevalence of pronounced vaginal bulging symptoms, recurrent POP, inguinal hernia, and hemorrhoids. The predominant LUTS were voiding symptoms (81.2% in males and 77.9% in females), followed closely by storage symptoms (66.2% in males and 74.7% in females). The median Qmax, PdetQmax, and PVR were 6 ml/sec, 18 cmH2O, 190 ml for male DU patients, and 8 ml/sec, 11 cmH2O, and 200 ml for female DU patients, respectively.

Risk factors for DU that were identified include age, neurological diseases (spinal disease, CVA in men, MS in women), diabetes and transabdominal surgery (colorectal, gynecological) that can cause pelvic denervation in women. DU patients commonly present with both voiding and storage symptoms. There is approximately twice the risk of having POP surgery and inguinal hernia, an eight-fold risk of hemorrhoids, and a three-fold risk of recurrent UTIs for females. This is thought to be secondary to increased intra-abdominal pressure during urinary straining.