BERKELEY, CA (UroToday Inc.) - A case-control study was carried out to identify any relationship between interstitial cystitis (IC) and irritable bowel syndrome (IBS) and depression by researchers at the University of Pennsylvania and recently reported in an article by Joseph Novi and colleagues. Virtually all cases of interstitial cystitis seen in the urogynecology outpatient clinic were captured by searching a medical record database. Subjects in the control group were recruited randomly during the same period from a general gynecology practice, where they were scheduled for an annual gynecologic examination. All subjects completed 3 standardized, validated questionnaires regarding symptoms of interstitial cystitis, irritable bowel syndrome and depression.

Symptoms of IC were assessed using the O'Leary-Sant interstitial cystitis symptom index. IBS was diagnosed using the Rome II standardized questionnaire. Symptoms of depression were evaluated by administering the Patient Health Questionnaire -9 Depression Module. Forty-six women with IC were compared with 46 women in the control group. The two groups were similar with respect to age, race, parity, previous pelvic surgery and postmenopausal hormone use. In the IC group, 67% had severe symptoms and 33% had mild disease.

Results were interesting and provocative. In the case group, 20 women were diagnosed with symptoms of IBS. In the control group (none of whom had symptoms of IC), 5 had symptoms of IBS. Major depressive symptoms were noted in 19 women in the IC group and 5 in the control group. Severe IC was associated with significantly higher risks of depression and IBS than mild disease. Urinary frequency and urgency were not associated with higher risk of depression, but as might be expected, bladder pain, abdominal pain, nocturia, and other bowel symptoms were associated with depression.

While the incidence of IBS was similar in women with mild and severe IC, women with severe IC were more likely to report more severe bowel symptoms. The authors believe this finding may be related to use of the Rome II questionnaire, in which abdominal pain is all that is required to make the diagnosis of IBS. The high incidence of IBS in this study in the IC patient group may be because the pain reported by some subjects may have been entirely of bladder origin, thereby, influencing the rate of IBS noted.

The interaction of mast cells with nerve cells to produce neurogenic inflammation and pain has been proposed as a common pathogenesis between IC and IBS. Chronic pain may be the link between IC and depression. This small study will provide the impetus to further evaluate these associations in large epidemiologic trials.

J. Urol. 2005 September 174:937-940