Constipation and fecal incontinence

Prevalence, impact, and definitions

Constipation and fecal incontinence (FI) can be classified as functional bowel disorders.¹ Functional bowel disorders are usually chronic (more than 3 to 6 months in duration at the time of presentation) and are attributable to the middle and lower gastrointestinal system. Constipation and FI are symptom-based diagnoses that may have multiple etiologies. Often, symptoms of constipation and FI occur simultaneously. Management will be discussed separately for constipation and FI, with a section on fecal impaction that can include symptoms of constipation and FI.

Constipation and fecal incontinence are common, underrecognized, and underreported conditions.

Chronic constipation disproportionately affects the elderly, with an estimated 40% of people older than the age of 65 experiencing the condition.²^,³ Women have 2 to 3 times more constipation than men. African Americans also exhibit increased risk. Many community-dwelling older adults use over-the-counter preparations, such as stimulant and bulking laxatives. Nearly 85% of physician visits for constipation result in a prescription for laxatives and more than $820 million are spent per year on over-the-counter agents. Few resources are available to health care providers to guide them in an evidence-based approach to this common problem.

FI occurs in up to 15% of older women and men.⁴^,⁵ FI is distressing, socially isolating, and associated with a possible increased risk of dependency in activities of daily living, morbidity, and mortality. Many older individuals with FI do not volunteer the problem to their health care provider, and providers do not routinely enquire about the symptoms. The condition can affect care providers of home-dwelling patients, with FI being cited as a reason for requesting nursing home placement. Because frail, older adults frequently have coexisting urinary symptoms (most often urinary incontinence) and other bowel symptoms (constipation), evaluation and management of other urinary symptoms and FI should be done simultaneously (see Chapter 23).⁴^,⁶ Even when noted by health care professionals, FI is often managed with absorptive or containment products, especially in the long-term care setting where it is most prevalent.

FI can result from constipation with stool impaction and may be more common in certain frail, older populations.⁷ In a recent study, 81% of residents in long-term care settings had symptoms of constipation and FI.⁸ However, the true prevalence of impaction and FI in nursing home residents and home-care settings has not been clearly identified. Because constipation with FI is difficult to diagnose, treatments should target constipation.

CASE 1 Angela McDonald

Angela McDonald is a 76-year-old woman with a 15-year history of constipation symptoms who visits your office with new bowel complaints. She consistently has had one to two bowel movements a week for the last several years and often feels as though she has incomplete evacuation. Most of her stools are very hard and are rarely smooth in contour. She has never noticed any blood in her stool, has no pain with defecation, and has not had a change in the caliber of her stools. Her weight and appetite have been stable.

Over the last 6 to 8 months, she admits to having weekly FI episodes where she notes leakage of mushy stool consistency without any prior warning. She takes a stool softener on most days and occasionally uses milk of magnesia when she has not had a bowel movement in 6 to 7 days. She notices that the milk of magnesia is no longer providing as much relief for her symptoms. She has not started any new medications and has had no dietary changes. Her medical history includes hypertension, gastroesophageal reflux disease, and mild urinary incontinence. She is very bothered because her episodes of FI have caused her to start wearing adult diapers on most days (she previously wore mini-pads for her urinary incontinence).

1. What is the most likely cause of Ms. McDonald’s bowel symptoms?

2. Do her current symptoms warrant further evaluation with a colonoscopy or other bowel imaging?

3. What additional tests are needed (if any) for her bowel symptoms?

4. Given her current bowel symptoms, what is the best initial treatment for Ms. McDonald’s symptoms?

Symptoms and definitions

Constipation is often associated with other abdominal complaints (pain, bloating, and gas), as well as decreased overall well-being. It may involve infrequent defecation, difficulty in passing stool, or incomplete evacuation of stool. Physicians often define constipation as infrequent passage of stool; however, patients often define it as straining to defecate or sensation of incomplete evacuation. In order for chronic constipation (CC) to be diagnosed, symptoms should be present for at least 12 weeks.

The Rome III criteria, published in 2006, define CC as symptoms that have persisted for the last 3 months with an onset at least 6 months prior to diagnosis, with the following three criteria being met:

The most common subtype of constipation is normal transit constipation.

1. Must include two or more of the following:

• Hard or lumpy stool in ≥25% of defecations

• Straining during ≥25% of defecations

• Sensation of incomplete evacuation for at least 25% of defecations

• Sensation of anorectal obstruction or blockage for ≥25% of defecations

• Manual maneuvers to facilitate ≥25% of defecations (e.g., digital evacuation, support of the pelvic floor)

• Fewer than three defecations per week

2. Loose stools are rarely present without use of laxatives

3. Insufficient criteria for irritable bowel syndrome (IBS)

Differentiating symptoms of chronic constipation from irritable bowel syndrome with constipation (IBS-C) and diarrhea (IBS-D) may not be as important in older adults, because age ≥50 years is associated with lower rates of IBS.⁵ However, management can differ between the two diagnoses. IBS-C is defined by recurrent abdominal pain or discomfort for at least 3 days per month in the previous 3 months (onset ≥6 months prior to the diagnosis) that is associated with at least two of the following:

1. Improvement of pain or discomfort upon defecation

2. Onset associated with change in frequency of stool

3. Onset associated with a change in form or appearance of stool

The International Continence Society provides a definition of FI that is the “involuntary loss of liquid or solid stool that is a social or hygienic problem.”⁹ Flatal incontinence may also be a bothersome symptom but is usually excluded from the definition for FI. Other bowel symptoms that may present with FI include rectal urgency, seepage of stool after bowel movements, incomplete evacuation, and loss of stool without any sensory awareness.