Retrograde cricopharyngeus dysfunction (R-CPD), also known as no burp syndrome, is a rare condition in which people are unable to burp or belch. It occurs when the cricopharyngeus muscle, a sphincter muscle that sits at the top of the esophagus, is unable to relax and, as a result, does not open to allow air to exit the esophagus.

Belching is a normal biological process through which the body ejects air from the esophagus and stomach into the throat, then out of the mouth or nose. Because people with R-CPD cannot burp, excess air builds up in the stomach and esophagus, leading to a range of symptoms that usually include loud gurgling noises from the neck and chest; bloating and discomfort in the neck, chest, and abdomen; and excessive flatulence. These symptoms can make social interactions embarrassing and, as a result, people with R-CPD often experience social anxiety or may even avoid social gatherings.

While doctors and researchers don’t know what causes R-CPD, in most cases, it is a lifelong condition. It can affect both children and adults, and many with the condition have never burped. Most people with R-CPD experience significant symptoms on a daily basis. Fortunately, with treatment, outcomes for most people are excellent.

When a person swallows, food and liquid move from the mouth to the end of the throat, where it meets the esophagus and the cricopharyngeus muscle. The cricopharyngeus muscle relaxes briefly, opening to allow the food and liquid to pass into the esophagus on its way to the stomach. Once the food and liquid have entered the esophagus, the cricopharyngeus tightens again, closing off the top of the esophagus.

With each bite of food and sip of a beverage, some air also gets swallowed and makes its way into the esophagus and stomach. Drinking carbonated beverages also delivers gas into the stomach. When enough air builds up in the stomach, it makes its way into the esophagus and causes the cricopharyngeus muscle to relax to allow the air to escape into the throat. This is known as a burp or belch. It is an important biological process that allows the body to rid itself of excess air in the stomach and esophagus.

In people with R-CPD, the cricopharyngeus muscle does not work properly. During swallowing, it relaxes as it should to allow food, liquid, and some air to enter the esophagus, but it does not relax to allow excess air in the stomach and esophagus to escape. As a result, air accumulates in the stomach, esophagus, and intestines, causing bloating and pressure in the abdomen, chest, and lower neck, and gurgling sounds from the chest and neck. In people with R-CPD, the abdomen may be distended or swollen, and because the air cannot leave through the esophagus, it instead passes through the intestines and exits the body as flatulence, which is often excessive.

Additional symptoms, outside of the lifelong inability to burp or belch, can include:

• Abdominal and/or chest bloating and pain
• Excessive flatulence
• Nausea
• Gurgling noises from the neck and chest
• Difficulty vomiting or fear of vomiting (emetophobia)

To diagnose R-CPD, your doctor will collect and review your medical history, perform a physical exam, and order one or more diagnostic tests.

Your doctor will usually begin to make a diagnosis by asking about your symptoms, including their severity and when they began. During a physical exam, your doctor will examine your throat and may perform a flexible nasopharyngoscopy. In this in-office procedure, your doctor will insert a flexible endoscope—a thin tube equipped with a light and camera—through your mouth or nose, down to your throat and upper esophagus.

To confirm a diagnosis, your doctor will inject botulinum toxin, or Botox®, into the cricopharyngeus muscle. R-CPD occurs when this muscle is unable to relax. Botox relaxes this muscle, so in people with R-CPD, the injection should allow them to burp and relieve symptoms. In this way, the injection can work both as a diagnostic test and a treatment.

Botox can be injected into the cricopharyngeus muscle either during an upper esophagoscopy or via electromyogram-(EMG)-guided Botox injection.

• In an upper esophagoscopy, you will be given general anesthesia, so you won’t be awake or feel any pain. Your doctor will insert an esophagoscope into your esophagus, visually locate the cricopharyngeus muscle, then inject it with Botox.
• In an EMG-guided Botox injection, your doctor uses an EMG device to locate the cricopharyngeus muscle before injecting Botox into it through the skin. In this procedure, two adhesive leads will be placed on the skin of your neck, and a special electrode needle will be placed on a syringe containing Botox. The doctor will then insert the needle into your neck, directing it toward the cricopharyngeus muscle. When the electrode needle reaches the muscle, it records its electrical activity. Next, the doctor injects the muscle with Botox. Often, the doctor will make multiple injections in different areas of the muscle.

The main treatment for R-CPD is a Botox injection into the cricopharyngeus muscle. Botox can be injected either as part of an upper esophagoscopy under general anesthesia or EMG-guided, as described above.

Most patients are able to burp and experience significant symptom relief within a week after a single injection. In some cases, however, doctors may recommend an additional Botox injection given several months later to patients whose symptoms continue.

A procedure called a partial myotomy of the cricopharyngeus muscle may be an option for patients whose symptoms do not adequately improve with Botox injections. In this minimally invasive surgical procedure, the surgeon inserts an endoscope through the mouth and into the throat. Next, the surgeon makes a cut partway through the cricopharyngeus muscle. This allows the muscle to relax, allowing air to exit the stomach and esophagus.

After getting a Botox injection into the cricopharyngeus muscle, people may experience one or more of the following side effects:

• A feeling that food “hangs” or gets stuck in the throat
• A feeling of a lump in the throat
• Acid reflux

These side effects typically resolve on their own after a few days or weeks.

As with any surgical procedure, undergoing partial cricopharyngeal myotomy comes with some risks for complications. Complications are rare but may include:

• Infection
• Damage to the esophagus
• Damage to nearby nerves (may result in hoarseness or vocal cord weakness)

With treatment, outcomes for most people with R-CPD are very good. One study found that after receiving a Botox injection into the cricopharyngeus muscle, over 99% of people were able to burp, and 95% experienced substantial symptom relief. The effects of a single Botox injection are expected to last around three months, but in practice, symptom relief often lasts for six to 12 months or longer. And for about 80% of people, the effects are thought to be permanent. For some, however, after Botox treatment, symptoms return, and an additional injection or a partial cricopharyngeal myotomy may be necessary to maintain symptom relief and the ability to burp.

“At Yale Medicine, we take pride in providing comprehensive care to those suffering from retrograde cricopharyngeus dysfunction,” says Michael Lerner, MD, a Yale Medicine ear, nose, and throat doctor who specializes in treating voice and swallowing disorders. “We listen to our patients, tailoring treatments to their preferences, and strive to make them active partners in their journey to relief. With a dedicated focus on this under-recognized disorder, our team conducts cutting-edge research to continually advance our understanding of R-CPD to ensure the best possible outcome for each and every patient.”