Interactions between bladder and bowel: clinical and experimental studies

Datum: 1 juli 2014

Locatie: University of Antwerp, Campus Drie Eiken, Building Q, Promotiezaal - Universiteitsplein 1 - 2610 Wilrijk (Antwerp)

Tijdstip: 17 uur

Organisatie / co-organisatie: Faculty of Medicine and Health Sciences

Promovendus: Michel Wyndaele

Promotor: Prof P. Pelckmans

Korte beschrijving: PhD defense Michel Wyndaele - Faculty of Medicine and Health Sciences


The lower urinary tract (LUT) and anorectum have a common embryological origin, the cloaca. They have a close anatomical relationship and a joint central and peripheral innervation to coordinate their function of storage and evacuation. Furthermore, there is increasing evidence that both organs interact, in physiological and in pathological conditions.

The clinical aim of this thesis was to further explore the concomitance of LUT and anorectal symptoms in patients.

We constructed a questionnaire in Dutch for the concomitant assessment of LUT and anorectal symptoms. The psychometric evaluation of this new questionnaire supported its validity and reliability, and for further studies the questionnaire was distributed to 555 urological patients (410 women and 145 men), to 211 gastroenterology patients (159 women and 52 men), and to a control group of 142 persons (104 women and 38 men).

A first clinical study showed that the prevalence of lower bowel symptoms is higher in female patients with urinary incontinence than in a control population, and that there is a correlation between the type of urinary incontinence and the presence of lower bowel symptoms.

The second clinical study showed that LUT symptoms are prevalent in female gastroenterological patients with complaints of functional constipation, fecal incontinence or both. We also showed that the presence of gastroenterological complaints influences the LUT symptoms with which female urological patients present.

The experimental aim of this thesis was to further investigate the inhibition of bladder activity by colorectal distension (CRD), the inhibitory recto-vesical reflex (IRVR), in a rat model. We showed that the IRVR is only initiated by noxious levels of CRD and can be modulated peripherally. The effect of CRD on bladder activity is enhanced mechanically, by increasing rectal balloon size, and pharmacologically, by intrarectal administration of a TRPA1 channel agonist. Inhibitory peripheral modulation was illustrated by intrarectal application of lidocaine, which reversibly abolished the IRVR.

In conclusion, we state that clinical findings can be translated to animal models to study interactions between the LUT and anorectum. Finally, we advise general practitioners, urologists and gastroenterologists to evaluate LUT symptoms in patients who consult for bowel symptoms and vice versa.