AIM To evaluate the quality and accuracy of websites written to the public on inflammatory bowel disease(IBD)(Crohn’s disease and ulcerative colitis) and assess their readability level.METHODS Google?, Bing?, and Yahoo? search engines were searched independently by three researchers in December 2014. Only English-language websites were selected on the basis of predetermined inclusion and exclusion criteria. Researchers independently evaluated the quality of each website by using the DISCERN and the HONcode instruments. The readability levels were calculated using two formulas; the Flesch-Kincaid Grade Level Index, and the Coleman-Liau Readability Index. The agreement between the evaluators was calculated using Cohen kappa coefficient.RESULTS Eighty-four websites were finally identified. Scores varied from a minimum DISCERN score of 18 to a maximum of 68 [mean ± SD, 42.2 ± 10.7; median = 41.5, interquartile range, interquartile range (IQR) = 15.8] and a minimum score of HONcode of 0.14 and a maximum of 0.95 (mean ± SD, 0.16 ± 0.19; median = 0.45, IQR = 0.29). Most of these websites were reviewed in 2014 and 2015 (n = 51). The creators of these websites were: universities and research centers(n = 25, 30%), foundations and associations (n = 15, 18%), commercial and pharmaceutical companies(n =25, 30%), charities and volunteer work(n = 9, 10%), and non-university educational bodies (n = 10, 12%). The Flesch-Kincaid Grade Level readability score(mean ± SD) was 11.9 ± 2.4 and the Coleman-Liau Readability Index score was 12.6 ± 1.5. Significant correlation was found between the two readability scores (R2 = 0.509, P = 0.001). The overall agreement between evaluators measured by Cohen kappa coefficient was in the range of 0.804-0.876; rated as “Good”.CONCLUSION The DISCERN and the HONcode scores of websites varied and the readability levels of most websites were above the public readability level. The study highlights the areas that need further improvement and development in patient education online materials about IBD. AIM To evaluate the quality and accuracy of websites written to the public on inflammatory bowel disease (IBD) (Crohn’s disease and ulcerative colitis) and assess their readability level. METHODS Google®, Bing®, and Yahoo® search engines were searched separately by three researchers in December 2014. Only English-language websites were selected on the basis of predetermined inclusion and exclusion criteria. Researchers independently evaluated the quality of each website by using the DISCERN and the HONcode instruments. The readability levels were calculated using two formulas; the Flesch -Kincaid Grade Level Index, and the Coleman-Liau Readability Index. The agreement between the evaluators was calculated using Cohen kappa coefficient .RESULTS Eighty-four websites were finally identified. Scores varied from a minimum DISCERN score of 18 to a maximum of 68 [ mean ± SD, 42.2 ± 10.7; median = 41.5, interquartile range, interquartile range (IQR) = 15.8] and a minimum score of HONcode of 0.1 4 and a maximum of 0.95 (mean ± SD, 0.16 ± 0.19; median = 0.45, IQR = 0.29). Most of these websites were reviewed in 2014 and 2015 (n = 51). The creators of these websites were: universities and research foundations and associations (n ​​= 15, 18%), commercial and pharmaceutical companies (n = 25, 30%), charities and volunteer work (n = 9, 10%), and non The Flesch-Kincaid Grade Level readability score (mean ± SD) was 11.9 ± 2.4 and the Coleman-Liau Readability Index score was 12.6 ± 1.5. Significant correlation was found between the two readiness scores (R2 = 0.509, P = 0.001). The overall agreement between evaluators measured by Cohen kappa coefficient was in the range of 0.804-0.876; rated as “Good”. CONCLUSION The DISCERN and the HONcode scores of websites varied and the readability levels of most websites were above the public readability level. The study highlights the areas that need further improvement and deve lopmentin patient education online materials about IBD.