Time, times and timing are key words in inflammatory bowel diseases (IBD).The leifmotif of this issue or World Journal of Gastroenterology is time. We have asked experts to review on the epidemiology of these diseases over time,the changes in innate immunity that could be present in the first time, and then the timing of key treatments. The correct time of using azathioprine, mercaptopurine, infliximab, cyclosporine and surgery are reviewed.We have chosen experts with not only great clinical expertise but also personal interest in clinical and basic investigation. Our goal in this monograph is to get an idea not only of the present but of the immediate future in some of the key management issues in IBD. To this end, we think that the authors are the most adequate.