Introduction Cyclic vomiting syndrome (CVS) is a functional gastrointestinal disorder (FGID) whose aetiology is poorly understood. It is characterised by acute episodes of vomiting and nausea followed by asymptomatic periods. Average age of symptom onset in adults is 22 years but average age of diagnosis is 31 years. This delay is probably because, until recently, CVS was considered to be a paediatric condition. Few studies have reported the prevalence in adults or risk factors for CVS. We examined this issue in patients attending gastroenterology clinics in a single secondary care centre.

Method 1002 consecutive adult patients seen in gastroenterology clinics completed the Rome III questionnaire and provided demographic data. Symptoms compatible with CVS were classified according to the Rome III criteria. All patients were investigated to a level deemed appropriate by the responsible physician. We recorded if vomiting symptoms were documented at the initial consultation and if a diagnosis of CVS was considered after negative investigations in those who met Rome III criteria and who were deemed to have “true” CVS. We compared demographics of those who did and did not have “true” CVS.

Results Of the 1002 patients, 920 provided complete questionnaire data. 112 (12.2%) had symptoms that met Rome III criteria for CVS. However, after investigation, 51 had an organic diagnosis, which included gastro-oesophageal reflux in 16 (31.4%), confirmed dysmotility in six (11.8%), coeliac disease in four (7.8%), hiatus hernia in three (5.9%), oesophageal adenocarcinoma in one, and peritoneal metastases in one. The remaining 61 (6.6%) were deemed to have “true” CVS (mean age 43.6 years, 80.3% female). Of these, only 21 (34.4%) had documentation of whether vomiting was present or absent at their initial consultation. After investigation, a diagnosis of CVS was considered in only four (6.6%) of these 61 patients. “True” CVS was associated with younger age, female gender, tobacco smoking, and presence of symptoms compatible with other FGIDs including irritable bowel syndrome, chronic proctalgia, proctalgia fugax, post-prandial distress syndrome, functional belching and functional chest pain (p<0.01 for all analyses). Only one patient with “true” CVS did not meet criteria for another Rome III FGID.

Conclusion Prevalence of “true” CVS in this adult secondary care outpatient population was 6.6%. Younger age, female gender, tobacco smoking and presence of symptoms compatible with other FGIDs were associated with “true” CVS. Presence of vomiting was poorly documented by consulting physicians and the diagnosis was considered in <10% of individuals who met criteria for the condition. These data provide clarification as to why diagnosis is often delayed in adults with typical symptoms.

Disclosure of Interest None Declared