A case-control study to examine any association between idiopathic detrusor instability and gastrointestinal tract disorder, and between irritable bowel syndrome and urinary tract disorder.

OBJECTIVE: To assess whether there are common malfunctions (e.g. of the autonomic nervous system and smooth muscle) that underlie disorders of the urinary and gastrointestinal tracts by determining whether there is an increased prevalence (i) of urinary symptoms in patients with irritable bowel syndrome (IBS) and (ii) of gastrointestinal symptoms in patients with idiopathic detrusor instability (IDI).

PATIENTS AND METHODS: Questionnaires were sent to patients with a diagnosis of IBS or IDI who were seen in the Departments of Gynaecology, Gastroenterology and Urology at the John Radcliffe and Churchill Hospitals, Oxford, during the 3 year period 1993-1995. The questionnaires were also distributed to control patients who were recruited from the day-surgery unit of the Churchill Hospital. Of 236 questionnaires sent out, 168 replies were analysed; 64 from patients with IBS, 49 from patients with detrusor instability and 55 from controls. The questionnaire included questions about micturition and defecatory behaviour (frequency, regularity, urgency, continence, pain, and ease in passing urine and stools).

RESULTS: Patients with IBS were more likely to experience certain urinary symptoms than controls (nocturia, urgency and some forms of urinary urge incontinence) and patients with IDI were as likely as patients with IBS to experience gastrointestinal symptoms more frequently than controls. Control patients showed an unexpectedly high probability of experiencing many of the gastrointestinal and urinary symptoms.

CONCLUSIONS: The frequent occurrence of symptoms in control patients makes the significance of the results less clear, but the association between certain symptoms of urinary tract disorder and patients with IBS, and of symptoms of gastrointestinal tract disorder with patients with IDI, suggests that they may share some common underlying dysfunction.