Background This study aimed to assess the dietary advice practice of UK and New Zealand (NZ) adult gastroenterologists in inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS).

Methods A questionnaire regarding dietary advice practice was emailed or mailed to all members of the British Society of Gastroenterology (n=983) and the NZ Society of Gastroenterology (n=54).

Results 363 questionnaires were returned in the UK (response rate 37%) and 51 in NZ (94%). More respondents gave specific dietary advice to more than 25% of their patients on IBS than IBD (84% vs 27% UK, 90% vs 55% NZ; p=0.001 for both) and gave advice about dietary exclusions to more than 25% of patients on IBS than IBD (61% vs 13% UK, 77% vs 14% NZ; p<0.001 for both). They were most likely to provide dietary advice to patients with small bowel Crohn's disease, difficult to control IBD, diarrhoea predominant IBS and difficult to control IBS. The majority of respondents agreed strongly or a little that dietary exclusion was effective in the treatment of IBS, compared to the minority in IBD (71% vs 39% UK, 84% vs 43% p<0.05 for both).

Conclusions UK and NZ gastroenterologists give dietary advice more commonly to IBS than IBD patients. The majority of gastroenterologists have some confidence in the use of dietary exclusion in IBS, the converse is true in IBD. However, the advice given is largely empiric and mostly comprises the exclusion of fibre, dairy and wheat.