Sir,I read with great interest the study by Al-Mofarreh and Al-Mofleh regarding the emerging inflammatory bowel disease (IBD) in Saudi Arabia.[1] It shows that there was none or only one patient of Crohn's disease (CD) during 1993-2000, but the number increased to three or four cases during 2001-2003 and then jumped to 174 cases in 2009. In contrast, there is not much change in the incidence of ulcerative colitis (UC), suggesting that the observed increase in CD is unlikely to be just due to increased awareness of IBD in the society or increased referral of patients to the clinic. There would be an urgent need to find out the cause of this dramatic increase since the early 2000s.In the last decade, a series of findings made me suspect that dietary chemicals like saccharin and sucralose may have played an important causative role in IBD through their inhibition of gut bacteria and the resultant impaired inactivation of digestive proteases and excessive damage of the mucus layer and the underlying gut tissue. This eventually led me to publish a paper in 2012 with a unified hypothesis on the etiology of IBD,[2] in which I included some evidences collected at that time, such as the remarkable increase of IBD in Alberta of Canada since the early 1990s, in Brisbane of Australia since the middle 1990s, in North California of the United States since the late 1990s, and in southeastern Norway since the middle 2000s, shortly after the approval of sucralose in Canada in 1991, in Australia in 1993, in the United States in 1998, and by the European Union in 2004. After the publication of that paper, more evidences are accumulating, such as the recent study showing a remarkable increase of pediatric IBD, also mainly CD, in Singapore since the beginning of this new millennium,[3] which happened again shortly after the approval of sucralose in Singapore in 1998. As Saudi Arabia approved sucralose around 2000, I recommend checking out the possible link between sucralose and the recent emergence of IBD in this country.