New and Evolving Treatments for Chronic Idiopathic Constipation

Key Takeaways

• Therapy for chronic idiopathic constipation is not one size fits all—the etiology of the condition will drive the treatment.
• Therapy options for primary constipation include physical therapy, over-the-counter medications, prescription medications, and a new mechanical option.
• Therapy for secondary constipation must address the cause and eliminate it, if possible.

When considering the treatment for chronic idiopathic constipation, we must realize that the etiology of chronic constipation often will drive the treatment. We first need to determine if we are addressing a case of primary or secondary constipation. If secondary, the cause should be identified and removed, if possible. In some cases, however, removing the cause may not be immediately possible. For instance, if your patient is experiencing opioid‑induced constipation, you may not be able to ask them to discontinue the opioid analgesic they are taking for their chronic pain. However, if someone is experiencing constipation related to a particular medicine for hypertension, you may be able to easily modify that medication and change to an equally effective one, avoiding the constipation side effect.

Medical Therapies—Over the Counter
For patients with normal transit constipation (the majority of patients with chronic idiopathic constipation), most guidelines will suggest that they start therapy with lifestyle modifications and over-the-counter medications. Lifestyle modifications generally take the form of increasing activity level, when possible.

Over-the-counter therapies include osmotic laxatives such as polyethylene glycol and fiber or bulking agents, which we often use together. We may get a synergistic effect with those combinations. We typically recommend soluble fiber—psyllium—because insoluble fibers such as bran often will be accompanied by significant bloating and actually may make constipation worse. Soluble fiber must be used in adequate doses of 1-2 tablespoons daily if patients are able to tolerate it. The major side effect from fiber is bloating, which often improves after 1 week of therapy.

Over-the-counter stimulant laxatives such as bisacodyl and senna products also are available. It is reasonable in some patients to consider combining over-the-counter laxatives with different mechanisms of action. These therapies are relatively inexpensive and generally well tolerated and have variable levels of efficacy. 

Prescription Therapies
There are 2 classes of prescription medicines for chronic constipation. The first is the secretagogues—lubiprostone, linaclotide, and plecanatide. The second class is prokinetics and currently consists of a single agent, prucalopride. All 4 of these medications have been approved by the FDA for chronic idiopathic constipation.

Some of these medicines are important in mitigating secondary constipation, as well, particularly opioid-induced chronic constipation. Opioids will cause constipation in approximately 40% to 50% of patients. Patients do not develop tolerance to the constipating effects of opioids like they do to some of the other symptoms or adverse events of opioid therapy, which can be a limiting factor for patients requiring such therapy, so it is important to be familiar with the available options to mitigate opioid-induced constipation.

Lubiprostone is approved by the FDA for opioid‑induced constipation. Linaclotide also has been shown to be effective for these patients but is not approved by the FDA for this indication. Plecanatide has not been evaluated in people with opioid-induced chronic constipation, but there is every expectation that it would be helpful in some patients. 

Peripherally acting μ-opioid receptor antagonists (PAMORAs) are the other class of medicines that should be highlighted. These agents block the binding of opioids to the opioid receptor and thus reverse or prevent the constipating effect of opioids. The PAMORAs do not help patients with non–opioid‑induced constipation. They do not have any promotility effect or prosecretory effect, so do keep that in mind when you’re thinking about using these agents.

Physical Therapy Treatments for Pelvic Floor Dysfunction
For patients with pelvic floor dysfunction, the treatment is pelvic floor therapy with a physical therapist who is skilled in the manipulation and training of the pelvic floor. Patients can derive a significant amount of benefit from this type of therapy in 5 or 6 sessions, but they must be willing to work on these exercises on their own at home. We have seen value in terms of improvement in 60% to 70% of patients with pelvic floor therapy, which is better than most medical therapies. 

It is important to recognize, however, that this approach is an adjunctive therapy. I believe that it is unrealistic to expect that pelvic floor therapy will improve all symptoms of constipation. You will still need to use laxative therapies in patients with pelvic floor dysfunction. Pelvic floor therapy will, however, enhance the way the laxatives work. 

Novel Therapeutic Options
Some very interesting therapeutic options are being developed. The one that I would like to highlight is the vibrating colon capsule. Patients ingest these capsules, and as they make their way through the gastrointestinal tract and reach the colon, they start vibrating on a prespecified frequency and duration. Studies of these devices have demonstrated significant improvement compared with placebo capsules that do not vibrate, for the endpoint of complete spontaneous bowel movements (bowel movements without the use of a laxative in which a patient feels completely evacuated, as well as spontaneous bowel movements).

One of these vibrating capsules has been approved by the FDA and will be available later this year; it will be interesting to see the level of patient acceptance to this therapy. It is a nonpharmacologic, mechanical therapy that can be taken orally, and it can be controlled through a smartphone application. This may prove to be a very interesting adjunctive therapy for some of our patients, perhaps for those with more refractory symptoms.

Your Thoughts?
What successes have you had with your patients with chronic idiopathic constipation? Join the conversation by adding a comment.