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Constipation, defined as less than three bowel movements per week, is one of the most common gastrointestinal disorders that primary care physicians and gastroenterologists face. It’s estimated that between 10% and 20% of Americans have constipation, and over $800 million a year is spent on over-the-counter (OTC) laxatives. Many patients have mild-to-moderate constipation, which is defined as infrequent stools or mild difficulty evacuating. However, some patients may experience chronic constipation, in which there is more frequent difficulty in eliminating, requiring chronic laxative use, straining, and often digital anal maneuvers to facilitate defecation. Chronic constipation can significantly decrease quality of life and is most often associated with abdominal discomfort, bloating, pain, and fatigue. Some patients may eliminate often but won’t feel like they’ve completely evacuated the rectum; they’ll continue to feel a sense of fullness in their stomach or in the rectum, leading to bloating, pain, and discomfort.

The first step to managing chronic constipation typically involves lifestyle modifications. Patients should be recommended to incorporate 20 g to 35 g of fiber a day into their diet and to exercise regularly, although these recommendations have not been proven to be effective in clinical trials. Various OTC medications may also be considered, including stimulant laxatives, bulking agents, and osmotic agents that draw more water into the bowel to lubricate and move stool more easily (eg, polyethylene glycol). If OTC medications are ineffective, lubiprostone is a prescription medication that may be more effective. The agent works on the chloride channels in the intestinal tract and stimulates the secretion of fluid in the bowel. Lubiprostone has been approved for patients aged 65 and older as well as for younger individuals with chronic constipation. In recent clinical trials, lubiprostone has shown to be twice as effective as placebo in producing a spontaneous bowel movement within the first 24 hours of starting the medication.

Tackle the Underlying Causes

It’s important to understand that medical therapies for increasing colonic motility may be ineffective due to possible secondary causes, which can vary considerably. Constipation may be associated with medication side effects, irritable bowel syndrome, cancer, mechanical obstruction of the bowel, diabetes, thyroidism, multiple sclerosis, or connective tissue problems. In addition, 25% to 50% of patients with chronic constipation may also have dyssynergic defecation, in which the constipation is associated with failure of the muscles of the anal canal and/or the pelvic floor to relax during the defecation process or the muscles contract, which prevent stool from being expelled. Dyssynergic defecation is usually treated with biofeedback, a method of retraining or conditioning of the muscles to relax during defecation using auditory or visual stimuli. Physicians should always consider dyssynergic defecation in patients who have been unresponsive to prescribed medications and laxatives or who report excessive straining during defecation.

Treatment Options Emerging

Due to the frequency of chronic constipation, the condition remains a hot topic for more research as investigators continue their hunt for more effective treatment options. Several trials are currently underway for medications that may help stimulate bowel movements through the use of serotonin-receptor agonists as well as medications that target peripheral opioid receptors and motilin receptors. Furthermore, guanylate cyclase receptor agonists have demonstrated an ability to increase transit throughout the gastrointestinal tract and to enhance chloride secretion, which is followed by fluid secretion into the gut lumen. This may offer potentially new treatment options for patients with chronic constipation.

Dr. Christie has indicated to Physician’s Weekly that she has or has had the following financial interest: Takeda Pharmaceuticals, Novartis, and Salix Pharmaceuticals.