Fecal incontinence (FI) is characterized by the unintentional passage of solid or liquid stool, which can lead to significant distress and disability. Risk factors for FI have been defined, and are closely aligned with the symptoms of Irritable Bowel Syndrome (IBS), including abdominal pain, loose or watery stool, hard or lumpy stool, and pain related to defecation. This study sought to determine the prevalence of FI in a general population, while also identifying participants endorsing IBS-like symptoms to comment on differences in FI symptom severity and impact for people with and without IBS.

Participants (n=765) were recruited online and asked to complete a survey that included questions about their gastrointestinal (GI) symptoms and their health related quality of life (HRQL). GI symptoms were measured with Rome IV criteria for IBS and FI. HRQL was measured with the SF-8 and FI-QoL, as well as other assessments for psychological variables, including the VSI, GI-Cog, and FFQ.

We found that 37.5% of the sample have experienced at least 1 episode of FI in their lifetime. Additionally, 27.8% of the sample have been formally diagnosed with IBS, or currently meet Rome IV diagnostic criteria for IBS. The frequency of FI episodes was found to be significantly associated with lifetime experiences of IBS. While 31.8% of participants that have never experienced IBS have experienced at least 1 episode of FI, 51.7% of participants endorsing lifetime IBS have also experienced at least 1 episode of FI. The interaction between FI and IBS yielded significantly different results in FI-QoL mean scores as well, indicating a clear difference in quality of life related to FI. The interaction effects revealed that FI quality of life is significantly worse for IBS-endorsing participants, even if they have never experienced an episode of FI. From these results, we conclude that FI is more common in an IBS population, but it is also quite high in the general population. Results for the psychological measures suggest that the difference lies not in the prevalence of FI, but in the impact of an FI episode on quality of life. Perhaps the fear of FI is more impairing than FI itself.