Effects of spicy foods and fatty foods on functional dyspepsia (FD) subtypes and the over-diagnosis of this condition in Thai patients.

Visceral hypersensitivity is a major pathogenesis of FD. Beside hypersensitivity to mechanical stimulation, hypersensitivity to chemicals (fat and/or capsaicin or chili) was also reported. Our study showed that 195/ 283(69%) of FD patients had symptoms induced by either spicy, fatty or sour food. This prevalence was significantly higher than healthy volunteers(12/100). Fatty foods induced mainly postprandial fullness symptoms, especially in post-prandial distress syndrome(PDS) subtype [proportion of patients with fullness in PDS vs. epigastrium pain syndrome(EPS)=15/60vs.12/127, p<0.05], where as spicy foods induced mainly burning symptoms in EPS (proportion of patients with burning in PDSvs.EPS=21/60vs.76/127, p<0.05). In addition, our study in 423patients, using a validated Thai version of the FBDR3 questionnaire demonstrated the over-diagnosis of FD as a consequence of under-diagnosis of IBS by Thai primary doctors. 71/86(83%) of patients who fulfilled the Rome III criteria for FD were diagnosed as FD by primary doctors whereas none of 43 patients who met the criteria for IBS was diagnosed as IBS. High prevalence of upper abdominal discomfort/pain and bloating reported in Asian IBS patients may caused FD over-diagnosis if bowel habit change was not taken into account. Conclusion: Our results suggested that EPS and PDS are 2 distinct conditions and should be managed differently especially dietary recommendation. Relationship to bowel habit symptoms should be explored in all dyspepsia patients.