Our findings show that the likelihood of having greater severity of several GI symptoms increased over time in individuals with fecal incontinence whether they ingested a fiber supplement or not. These symptoms included flatus, belching, a feeling of fullness, and bloating. Flatus and bloating are lower GI symptoms while belching and a feeling of fullness are upper GI symptoms. The absence of a significant difference in symptoms between the placebo and fiber groups suggests that individuals with fecal incontinence (and no additional fiber intake) have adverse GI symptoms similar to those associated with dietary fiber intake or experience a placebo effect.