While the co-existence of fecal incontinence (FI) and constipation is well-recognized in the pediatric and geriatric population, the authors of this article suggest that the relationship is under-appreciated in the adult population. Samuel Nurko, MD, and Mark Scott, PhD, describe the association between pediatric functional fecal incontinence and constipation, stool retention, and incomplete evacuation. In adults, they point out, constipation may also be related to pelvic floor dysfunction and denervation. The negative impact on quality of life creates the need for these issues to be addressed more readily, both in adults and in children.
The study mentioned above cites a prevalence of fecal incontinence in school-aged children of 1-4%. The majority of the research cited in the article report that this incontinence is related to underlying constipation. Factors that may contribute to childhood holding of stool or to rectal dysfunction include constipation early in childhood, painful bowel function, "coercive toilet training practices and social stressors", fecal impaction, and treatments involving anal manipulation. It has been surprising to me how many adult patients describe psychologically stressful childhood associations with bowel function. Fortunately, the psychological stress, low self-esteem, and decreased quality of life that is associated with childhood bowel dysfunction improves with successful treatment of the condition. Childhood behavioral issues including bullying, disruptive behavior, and social withdrawal also are noted to improve following improvement in fecal issues, suggesting that the terrible social impact of fecal incontinence may be to blame for some of the behavioral issues.
In relation to the adult population, the authors state that while the coexistence of constipation and FI may not be known, constipation has been shown to be an independent risk factor for FI and incomplete emptying is associated with fecal incontinence. In the patient who has poor emptying of the bowels, overflow can occur, and this type of leakage is then associated with constipation. It follows, then, that treatment of the constipation should improve the fecal leakage. Three mechanisms are described regarding the pathophysiology of incontinence caused by constipation: overflow due to fecal impaction; post-defecation leakage caused by rectal stool retention from a rectal evacuatory disorder; and general pelvic floor weakness or denervation. Certainly, neurological or other disease conditions can cause bowel dysfunction, yet this article focuses on "functional" constipation not caused by such diseases.