Fecal Incontinence The reported prevalence of fecal incontinence varies between 2% and 3% for community-dwelling individuals, 3% to 17% for those of increased age, and 46% to 54% for nursing home residents (12). A prevalence of 28% has been reported among patients seeking benign gynecologic care and 36% of primary care patients surveyed (13,14). The prevalence of fecal incontinence in the United States is expected to increase 59% from 10.6 million in 2010 to 16.8 million in 2050 as the population ages (15). Epidemiologic studies of fecal incontinence are compromised by social stigmata and the lack of a uniform definition. Definitions of fecal incontinence vary with respect to the type of material passed (solid, liquid, or gas), the frequency and duration of events (once in a lifetime to twice a week), and the impact on quality of life. Most authors agree that the true prevalence of this condition is underestimated in the current scientific literature. A large health survey in the United States found age, female gender, physical limitations, and poor general health to be independent risk factors associated with fecal incontinence (16).
Fecal incontinence has tremendous psychosocial and economic implications for individuals and society as a whole. The loss of such a basic function can be emotionally devastating, leading to poor self-esteem, depression, social isolation, and decreased quality of life (13,14,17). Fecal incontinence is the second leading reason for nursing home placement in the United States, even though less than one-third of individuals with this condition seek medical attention (13,17). The overall annual cost to treat fecal incontinence is difficult to pinpoint, but accounts for more than $400 million per year in the cost of adult incontinence products alone (17).
Symptom-Based Approach to Colorectal Disorders
Several medical conditions cause defecatory dysfunction, fecal incontinence, or combined symptoms. Following is the differential diagnosis—a proposed classification system based on systemic factors, anatomic and structural abnormalities, and functional disorders.
Disordered Defecation Causes of defecatory dysfunction have traditionally been divided into systemic disorders and idiopathic constipation (all nonsystemic causes). Idiopathic constipation can be subdivided into anatomic and structural abnormalities and functional disorders (Table 28.1).
Diabetes, hypothyroidism, and pregnancy are the most common endocrinologic systemic factors that cause constipation, and all have a component of decreased gastrointestinal motility and intestinal transit. In one study, gastrointestinal symptoms were present in 76% of patients with diabetes, including constipation, which occurred in 60% (18). In patients with diabetes, constipation is believed to be secondary to intestinal autonomic neuropathy, resulting in delayed or absent gastrocolic reﬂex and decreased bowel motility. This enteric neuropathy may also cause gastroparesis and diarrhea. Although diabetes has been classified with the endocrinologic causes, it should also be grouped with the enteric neuropathies. Pregnancy is not considered a disease state; however, there is an 11% to 38% prevalence of constipation that is believed to result from the effect of progesterone on smooth muscle (19,20). Iron supplements and prior constipation treatment are also associated with constipation during pregnancy (20).