Retrograde cricopharyngeus dysfunction (R-CPD)

The upper oesophageal sphincter is a ring of muscle at the top of the gullet. Its main part is the cricopharyngeus muscle. It relaxes when you swallow and stays closed at other times, which stops stomach contents reaching the airway. A 2024 review in the Journal of Clinical Medicine explains that in a normal burp, gas moves up from the stomach, the gullet stretches, the upper sphincter relaxes and the gas escapes.

In R-CPD, the review says the sphincter fails to relax when the gullet is stretched by gas, so the person cannot burp and the air remains trapped. The substernal pressure continues until the muscles of the gullet swallow the gas back down. The gas moving up and down is thought to produce the gurgling sound many people hear.

The review says diagnosis is based mainly on four features: an inability to burp, abdominal fullness or bloating, gurgling noises in the chest or lower neck, and excessive flatulence. Occasional chest pressure or pain behind the breastbone has also been reported. An Italian study of 67 patients found that 84% reported a complete inability to burp, and that bloating, gurgling and flatulence affected most of them.

Some people also report painful hiccups, difficulty vomiting, or a fear of vomiting. In that Italian group, 85% said they avoided certain foods or drinks, particularly carbonated drinks, and 76% avoided social situations to some extent. The review describes anxiety, social isolation and time missed from work or school.

• Never or rarely being able to burp, often for as long as you can remember.

• Uncomfortable bloating, especially after eating or fizzy drinks.

• Loud gurgling from the neck or chest.

• A lot of wind from the bowel.

• Chest pressure or pain after meals.

The exact cause is not known. The review describes a leading hypothesis that the lower sphincter relaxes normally and lets gas up, but the upper sphincter does not respond properly. It also notes that pressure recordings before treatment in some patients showed a paradoxical rise in pressure at the sphincter, which may be a learned response to avoid aspiration, although further research is needed on the role of behaviour.

Because botulinum toxin often leads to lasting benefit after its pharmacological effect has worn off, the review suggests that a brief period of muscle weakness may allow people to learn the burp reflex that was absent. This remains a hypothesis. The doctor will want to exclude other problems before settling on this diagnosis.

The review states that R-CPD is a diagnosis of exclusion that relies mainly on clinical history, and that the usual work-up is variable and often unremarkable. Published case series have not identified a test that reliably diagnoses it, though investigations such as endoscopy, barium swallow or oesophageal manometry are used to exclude other conditions. Pressure testing after a carbonated drink is being studied.

The review adds that a response to a botulinum toxin injection into the cricopharyngeus has been considered both diagnostic and therapeutic. People should be aware that the review notes growing awareness from patient-led online communities, and that many people arrive having self-diagnosed. A proper clinical assessment is needed, since bloating has many other causes.

The NHS bloating page lists constipation, food intolerance, coeliac disease and irritable bowel syndrome among causes, and says to see a GP if you feel bloated regularly, or have weight loss or blood in the stool.

The review describes botulinum toxin injection into the cricopharyngeus as the mainstay of treatment. In a study of the first 200 patients treated, 95% experienced relief of the main symptoms and about 80% of them had durable resolution at 6 months. Reported success rates in the review range from 88.2 to 95%, and repeat injections often work if symptoms return. Results in other series can be lower: the Italian study found 55.2% of patients were responders at one month with low-dose, one-sided injections.

Injection may be done in the operating room or, at some centres, in the office guided by electromyography. The review reports a higher success rate in the operating room (90.2%) than in the office (64.9%) in one comparison, with similar side effect rates.

The most common side effect is temporary difficulty swallowing lasting 1 to 4 weeks, and a small number of people have vocal fold weakness from spread of the toxin. Balloon dilation and a surgical cut of the muscle (myotomy) are described mostly in case reports. A speech and language therapist may have a role, but a formal therapy plan has not been developed.

The review says many people change what they eat and drink, avoid exercise or social events, and try online remedies. One of these is self-induced vomiting to release trapped air, sometimes called air vomiting. This is not recommended as a regular approach, and anyone doing it frequently should tell a doctor.

The NHS bloating page suggests simple measures that apply to any bloating: eating smaller, more frequent meals, chewing with the mouth closed to avoid swallowing air, avoiding fizzy drinks, and taking regular exercise. A pharmacist can suggest medicines such as simeticone. These do not treat R-CPD but may ease discomfort.

See a GP if you cannot burp and it affects eating, sleep, activity or mood. Seek urgent advice if bloating comes with vomiting, a stomach ache, fever, a lump in the tummy, or inability to pass wind or stool, as the NHS lists these as reasons for an urgent GP appointment or NHS 111. Call 999 for severe sudden abdominal pain, vomiting blood or severe breathing difficulty.

An ENT surgeon, gastroenterologist or specialist swallowing service is the usual route for assessment. Because the condition is new and the evidence base small, ask the clinician about their experience, the options, and the risks of each.