Background/Aims: The Leuven Postprandial Distress Scale (LPDS) is a validated patient reported outcome (PRO) measure for functional dyspepsia (FD)/postprandial distress syndrome (PDS) patients according to Rome III criteria. However, meal-related nausea or epigastric pain, part of PDS in Rome IV, were not addressed in this construct. Also, focus groups identified fatigue as a frequently reported complaint for which the European Medicines Agency requested further analysis. Our aim is to validate the LPDS in FD/PDS as defined by Rome IV criteria and to optimize the model by assessing the value of adding extra items to this questionnaire. Methods: The questionnaire was validated in 3 different Rome IV FD/PDS patient cohorts recruited for controlled clinical trials. Additional questions in the diary regarding symptom relationship to meal and fatigue were evaluated. Anchor scores were the patient assessment of gastrointestinal symptom severity index, Short-form Nepean dyspepsia index, the overall treatment evaluation and overall symptom severity questionnaires. Results: The LPDS Construct validity was confirmed for Rome IV-defined PDS. Psychometric analysis did not support inclusion of fatigue, nausea, meal-related or meal-unrelated, and meal-related epigastric pain, due to low loading or poor model fit. Conclusions The LPDS questionnaire showed good reliability and responsiveness, and can be confidently used as a validated tool in Rome IV PDS populations. Data did not support adding accessory symptoms to the construct, due to low loading or poor model fit.

Background/Aims: Systemic sclerosis (SSc) often is complicated by small intestinal bacterial overgrowth (SIBO). A systematic review and meta-analysis thus examined the prevalence of SIBO in SSc (SSc-subtypes), identify risk factors for SIBO in SSc and the effects of concomitant SIBO on gastrointestinal symptoms in SSc. Methods: We searched electronic databases until January-2022 for studies providing prevalence rates of SIBO in SSc. The prevalence rates, odds ratio (OR) and 95% confidence intervals (CI) of SIBO in SSc and controls were calculated. Results: The final dataset comprised 28 studies with 1112 SSc-patients and 335 controls. SIBO prevalence in SSc-patients was 39.9% (95% CI, 33.1-47.1; P= 0.006), with considerable heterogeneity, (I 2 = 76.00%, P < 0.001). As compared to controls, there was a 10-fold increased SIBO prevalence in SSc-patients (OR, 9.6; 95% CI, 5.6-16.5; P< 0.001). The prevalence of SIBO was not different in limited cutaneous SSc as compared to diffuse cutaneous SSc (OR, 1.01; 95% CI, 0.46-2.20; P = 0.978). Diarrhea (OR, 5.9; 95% CI, 2.9-16.0; P = 0.001) and the association between SIBO in SSc and proton pump inhibitor use (OR, 2.3; 95% CI, 0.8-6.4; P = 0.105) failed statistical significance. Rifaximin was significantly more effective as compared to rotating antibiotic in eradicating SIBO in SSc-patients (77.8% [95% CI, 64.4-87.9]) vs 44.8% [95% CI, 31.7-58.4]; P < 0.05). Conclusions There is a 10-fold increased prevalence of SIBO in SSc, with similar SIBO prevalence rates in SSc-subtypes. Antimicrobial therapy of SIBO-positive SSc-patients with diarrhea should be considered. However, the results must be interpreted with caution due to substantial unexplained heterogeneity in the prevalence studies, and the low sensitivity and specificity of the diagnostic tests suggesting that the reliability of the evidence may be low.