A Finnish study showed that among 84 of 155 patients with a structuring phenotype, only 26 (17%) patients required surgery over the 2-year study period.27 Conversely, anti-TNF-α antibodies induced small bowel stenoses in 8 of 15 (53.3%) patients after 6-22 maintenance infusions.28 In another prospective study investigating the frequency of small bowel obstruction in CD stricture patients after IFX or adalimumab, 2 of 9 (22.2%) had bowel obstruction requiring surgical resection.29 However, data on the development of bowel obstruction after UST is lacking. This evidence concerns the gene TNF and intestinal obstruction.