Materials and Methods

This case-control study was approved by our local institutional review board. It was a secondary analysis of a previously reported study investigating the functional bowel symptoms and anorectal disorders in patients with advanced pelvic organ prolapse. Subjects were defined as those who presented to a tertiary urogynecology clinic with advanced pelvic organ prolapse (stage 3 or 4). Controls were defined as subjects presenting to a general gynecology or women’s health clinic for annual examinations with normal pelvic support (stage 0 or 1) and without urinary incontinence. Demographic, historical, and physical examination information was collected.

All subjects completed a validated questionnaire on functional bowel disorders (Rome II Modular Questionnaire) as well as a generalized (Short-Form Health Survey-12) and a condition-specific (Pelvic Floor Distress Inventory-20) health-related quality-of-life scale. In the original study, assuming a baseline prevalence of constipation in the control group of 16%, a sample size of 123 subjects in each group provided 80% power to detect a difference between this baseline prevalence and an increased prevalence of 32% in the prolapse group, using a 2-group continuity-corrected χ ² test with a 0.05 2-sided significance level.

For this analysis, the primary outcome was abdominal or pelvic pain based on the subject’s responses to specific pain-related questions abstracted from the Short-Form Health Survey-12 Questionnaire, Pelvic Floor Distress Inventory-20 (PFDI-20) Questionnaire, and the Rome II Modular questionnaires.

The following questions from the PFDI-20 were used to elicit whether the study subjects had symptoms of pelvic or lower abdominal pain: “Do you usually experience pressure in the lower abdomen”; “do you usually experience heaviness or dullness in the pelvic region”; and “do you usually experience pain or discomfort in the lower abdomen or genital region?” The question, “During the past 4 weeks, how much did pain interfere with your normal work (including both housework and work outside the home)” was abstracted from the Short-Form Health Survey-12 Questionnaire, whereas 2 questions (“In the last 3 months, did you often have discomfort or pain in your abdomen” and “In the last 6 months, did you have pain in your abdomen all the time [continuously] or most of the time [nearly continuously] [this should not be related to your menstrual cycle or period]”) were abstracted from the Rome II Modular Questionnaire.

The possible responses to the questions were “yes” or “no.” If the subjects answered “yes” to the questions from the PFDI-20, they were prompted to characterize the degree of bother as “not at all,” “somewhat,” “moderately,” or “quite a bit.” Subjects who answered “yes” but reported that the pain was “not at all bothersome” were also categorized as no pain. Subjects were arbitrarily characterized as having bothersome pain symptoms if they reported the degree of bother as “moderately” or “quite a bit” when answering the PFDI-20 questions.

Categorical data comparing lower abdominal and pelvic pain between cases and controls were analyzed using the χ ² statistic and the Student t test for continuous data. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to estimate the relationship between lower abdominal and pelvic pain with advanced organ prolapse. Multiple logistic regression was used to adjust for potential confounding variables and was presented using adjusted ORs with 95% CIs. Statistical analysis was performed using JMP 8.0 (SAS Institute, Cary, NC), and statistical significance was set at P < .05.