Managing patients with constipation, which leads to 8 million visits to clinicians each year, requires staying up-to-date on the most effective ways to diagnose and treat various types of the condition, according to a review published in JAMA.
In the last 5 years, several important treatments for constipation have been developed. These include updates for laxatives and promotility agents; new treatments for opioid-induced constipation (OIC); and the identification of functional defecation disorders. Despite these advances, the treatment approach for chronic idiopathic constipation (CIC) has remained largely unchanged.
Patients can experience constipation from several underlying causes, including a primary motor disorder involving the colon, a defection disorder, an adverse reaction to a drug, or due to various diseases.
A clinical evaluation of constipation should include:
- Duration of symptoms
- Frequency/consistency of stools
- Presence of excessive straining
- Feeling of incomplete evacuation
- Use of manual maneuvers during defecation
- Excluding any potential organic causes or adverse drug reactions
Current pharmacologic agents for constipation
There are 4 major groups of laxatives available in the United States. The 1st 3 groups are available over the counter (with the exception of lactulose), whereas the last group requires a prescription.
- Bulk agents: psyllium, methylcelluose, calcium polycarbophil, wheat dextrin
- Nonabsorbed substances: PEG 3350, lactulose, magnesium salts
- Stimulants: bisacodyl, senna
- Secretory drugs: lubiprostone, linaclotide
Stimulant laxatives remain underused for the treatment of constipation due to 2 concerns: 1) that they can damage the colon and cause the patient to become dependent on them and 2) that there is a lack of evidence to prove their efficacy. However, there is no evidence that the first concern is true, and there are now several recent, robust studies that demonstrate the safety and efficacy of stimulant laxatives.
There is a dearth of studies that compare the efficacy of older laxatives with newer drugs (such as secretory drugs). Until more research is done, clinicians are advised to consider the cost and potential adverse effects associated with a drug when recommending a course of treatment for constipation.
No one treatment course is effective for all patients with constipation. Instead, clinicians should work with their patient to adjust the treatment plan until they find which treatment (or combination of treatments) is most effective.