Constipation: Uncomfortably Common

Constipation is defined as a condition in which an individual has fewer than 3 bowel movements each week or has bowel movements that are hard and difficult to pass.

It is considered to be a common gastrointestinal complaint affecting an estimated 42 million individuals in the United States.1 Causes include certain medical conditions and pharmacologic agents, physiologic and psychological issues, and lifestyle or dietary habits (Table 1^1,2). Pharmacists are in a pivotal position to aid patients in the selection of the best products to treat constipation, as well as to identify patients with a higher risk of developing constipation due to the use of certain pharmacologic agents (Online Table 2^1,3).

Constipation can affect anyone at any age, but it does occur more frequently during pregnancy, after childbirth, after surgery, and from taking certain medications.² Although most cases are easily managed with proper treatment, some individuals suffer from chronic constipation that can lead to other complications, such as hemorrhoids, anal fissures, and fecal impaction.^2-4 Patients with chronic or repeated episodes of constipation should be advised to seek further medical care from their primary health care provider when warranted.

Signs and Symptoms

Whereas the incidence and severity of constipation vary from patient to patient, the most common signs and symptoms include the following^1,2:

• Stomach discomfort or cramping that is resolved by a bowel movement

• Straining during bowel movements

• Fewer bowel movements than usual

• Bloating or abdominal discomfort

• Hard, compacted stools that are difficult to pass

Prevention and Treatment

A host of nonprescription products are on the market for preventing and treating constipation (Online Table 3^2,4). The selected treatment depends on the cause, severity, and duration of the constipation. Treatments may include one or more of the following: increasing dietary fiber; using fiber supplements, stimulant laxatives, saline laxatives, osmotic laxatives, and/or stool softeners; and making exercise and lifestyle modifications. Prior to recommending any product, pharmacists should ascertain if self-treatment is appropriate and refer patients to their primary health care provider for further evaluation and treatment, when warranted.

Table 2: Examples of Drugs that May Induce Constipation^1,3

• Analgesics
• Antacids
• Anticholinergics
• Anticonvulsants
• Antimuscarinics
• Benzodiazepines
• Calcium channel blockers
• Calcium supplements
• Diuretics (eg,hydrochlorothiazide, furosemide)
• Antispasmodics
• Iron supplements
• Hyperlipidemic agents
• Hypotensives (eg, angiotensin-converting-enzyme inhibitors, beta blockers)
• Muscle relaxants
• Opioids
• Parkinsonian agents
• Sedative hypnotics
• Sucralfate
• Tricyclic antidepressants
• Vinca alkaloids

Bulk-Forming Agents

As a group, bulk-forming agents—such as methylcellulose, polycarbophil, and psyllium—are the treatment of choice in the majority of constipation cases since their mechanism of action closely resembles the physiologic mechanism that promotes defecation.² They are indicated as short-term therapy and prophylactically in patients who should refrain from straining during a bowel movement.²

These agents work by dissolving or swelling in the intestinal fluid of the small and large intestines and form emollient gels that stimulate peristalsis, resulting in a bowel movement.^2,4 The usual onset of action is 12 to 24 hours after administration, but can take up to 72 hours.⁴ Bulk-forming agents are available in powders, tablets, capsules, chews, wafers, and gummies.² Patients should be advised to take each dose with at least 8 oz of fluid to avoid the potential for an intestinal block.^2,4 The use of these types of laxatives should be avoided in those with swallowing difficulties or esophageal strictures and may be inappropriate for patients who must restrict fluid intake.²

Internal server error