Development and validation of a knowledge, attitudes and practices questionnaire in the dietary management of irritable bowel syndrome.

OBJECTIVE: To develop and validate a questionnaire assessing knowledge, attitudes and practices in the dietary management of IBS. SUBJECTS/METHODS: An initial pool of 151 questions was generated addressing three domains (knowledge, attitudes, practices). Academic/senior clinical dietitians (n = 5) provided written feedback and a focus group (n = 4 gastroenterology dietitians) was undertaken to evaluate content and face validity of the question-items. Items considered irrelevant were removed and the refined questionnaire was administered to dietitians with different levels of IBS experience (n = 154) for further psychometric testing. Item reduction analysis was assessed by item difficulty index, discrimination index and point-biserial correlation. Construct validity was assessed via principal component analysis (PCA) and the 'known-groups' method. Internal reliability was assessed by Kuder-Richarson Formula 20 and Cronbach's alpha coefficient and external reliability by interclass correlation coefficient among participants who completed the instrument at baseline and two weeks later (n = 28). RESULTS: Face and content validity resulted in the removal of 61 items from the initial 151 items. Psychometric testing was applied to the refined 90-item questionnaire administered to participating dietitians, resulting in the final 46-item questionnaire. Six factors were extracted by PCA with varimax rotation explaining 59.2% of the total variance. Partial confirmatory factor analysis showed an acceptable model fit (χ2/df = 2.11, CFI = 0.97, TLI = 0.96, RMSEA = 0.08, SRMR = 0.05). Significant differences were found in sum scores among dietitians with different levels of IBS experience. Internal reliability was >0.7 for each factor. External reliability was >0.6 for each factor and >0.7 for overall items of each domain. CONCLUSION: A validated questionnaire to use in practice and research to assess knowledge, attitudes and practices in the dietary management of IBS has been developed.

Processing Apples to Puree or Juice Speeds Gastric Emptying and Reduces Postprandial Intestinal Volumes and Satiety in Healthy Adults.

BACKGROUND: Whole apples produce greater satiety than processed apples, but the underlying mechanisms remain unclear. OBJECTIVE: Our aim was to assess the intragastric processing of apple preparations and the associated small and large bowel contents using MRI. METHODS: An open label, 3-way crossover, randomized, controlled trial. Eighteen healthy adults (mean ± SD age, 25 ± 4 y; BMI, 22.7 ± 3.5 kg/m2) underwent serial MRI scans on 3 occasions separated by 7 d, after consumption of isocaloric (178 kcal) portions of either whole apples, apple puree, or apple juice. Gastric emptying, small bowel water content (SBWC; primary endpoint), were measured at baseline and at 45 min intervals (0-270 min) postmeal ingestion. Fullness and satiety were also assessed at each time point. Treatment effects between groups were analyzed using ANOVA. RESULTS: Gastric emptying half-time (GE t50) was greater (P < 0.0001) after participants consumed whole apple (mean ± SEM), 65 (3.3) min compared with when they consumed apple puree (41 [2.8] min) or apple juice (38 [2.9] min), times that did not differ. Postprandial area under the curve (AUC) (135-270 min) SBWC was also greater for whole apples than puree (P = 0.025) and juice (P = 0.0004) but juice and puree did not differ. AUC for fullness and satiety (0-270 min) postingestion was also greater (P = 0.002 and 0.004, respectively) for whole apple compared with juice but juice and puree did not differ. CONCLUSIONS: Gastric emptying is slower after whole apple consumption causing a greater sensation of fullness and satiety than puree or juice in healthy adults. Whole apples increased small bowel and colonic contents during the later phase of the study which may be relevant for subsequent food consumption.This study was registered at clinicaltrials.gov as NCT03714464.