Constipation: Uncomfortably Common

JULY 08, 2015
Yvette C. Terrie, BSPharm, RPh
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 11,2). 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 21,3).

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 following1,2
• 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 32,4). 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 Constipation1,3
  • 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

Table 3: Examples of OTC Products for Treating and Preventing Constipation
Brand Name (Active Ingredient)
Benefiber Products (wheat dextrin)
  • Benefiber Fiber Caplets
  • Benefiber Plus Heart Health Powder
  • Benefiber Chewable Tablets
  • Benefiber Powder
  • Benefiber for Children
  • Benefiber Powder Plus Calcium (300mg calcium)
  • Benefiber Stick Packets
Citrucel Products (methylcellulose)
  • Citrucel Powder with Smart Fiber (also available in a sugar-free option)
  • Citrucel Caplets with Smart Fiber
Fiber Choice (inulin)
Fibercon Caplets (Calcium Polycarbophil)
Hydrocil (Psyllium)
Konsyl Products (psyllium hydrophilic mucilloid)
·         Konsyl Fiber Caplets
·         Konsyl Original
·         Konsyl Easy Mix
·         Konsyl Fiber Easy to Swallow Capsules
L’il Critters Fiber Gummy Bears
Little Remedies Fiber Gummies
Metamucil Products (psyllium husk)
  • Metamucil Original
  • Metamucil Fiber Powder Drink Mixes
  • Metamucil Fiber MultiGrain Wafers
  • Metamucil Fiber MultiHealth Capsules
  • Metamucil Fiber Singles
Metamucil Clear and Natural (inulin)
Phillips Fiber Good Gummies
Unifiber (powdered cellulose)
Vitafusion Fiber Well Gummies
Vitafusion Fiber Well Weight Management Gummies
Emollient Agents
  • Colace Capsules (docusate sodium)
Lubricant Laxatives
  • Fleet Mineral Oil Enema (mineral oil 100%)
  • Kondremul Emulsion (mineral oil 55%)
Saline Laxatives
  • Magnesium Citrate Oral Solution
  • Fleet Enema (monobasic sodium phosphate and dibasic sodium)
  • Pedia-Lax Enema (monobasic sodium phosphate and dibasic sodium)
  • Phillip's Milk of Magnesia Suspension (magnesium hydroxide)
Hyperosmotic Laxatives
  • Fleet Gylcerin Suppository (gylcerin 2 g)
  • MiraLAX (polyethylene glycol)
Stimulant Laxatives
  • Dulcolax Tablets (bisacodyl)
  • Senokot Tablets and Senokot Xtra (sennosides)
  • Fletcher's Laxative for Kids (senna concentrate)
Combination Laxatives
  • Senokot S tablets (sennosides and docusate sodium)