Last edited 09/2023 and last reviewed 09/2023

Achalasia is an oesophageal smooth muscle motility disorder:

  • failure of relaxation at the lower oesophageal sphincter
  • progressive dilatation, tortuosity, incoordination of peristalsis and hypertrophy of the oesophagus
  • functional obstruction at the lower end of the oesophagus.

Achalasia may occur at any age but particularly in the second to fifth decade of life with peak incidence between ages 30 to 60 years. Males and females are affected equally (1,2).

Annual incidence is about 1 per 100,000 and prevalence of 10 per 100,000 (1).

Chronic opioid use (COU)

  • study evidence revealed that chronic opioid use (COU) was associated with an increased frequency of oesophageal dysmotility disorders (ODD) e.g type III achalasia (pooled OR 4.15, 95% CI 2.15-8.03, p<0.0001) but not type I or II achalasia (3)
    • study authors stated that COU should be considered as a risk factor when diagnosing ODD