MCP-1 also remained significantly associated with delayed RoBF following adjustment to potential risk factors of prolonged postoperative ileus such as male gender, older age, prolonged operation time, cancer dissemination, blood transfusions, ileostomy, AL, extent of surgery, obesity, and ASA ≥ 3 [40], of which only the length of surgery, dichotomized, was found significant. This evidence concerns the gene CCL2 and obesity due to melanocortin 4 receptor deficiency.