IL6 and irritable bowel syndrome: According to the t test, the group of IBD patients with poor sleep, in comparison to group without sleep abnormalities had significantly higher levels of serum IL-6, IL-17 and IL-23 (p = 0.003,  t  =  − 3.327, df = 20;  p  = 0.004,  t  =  − 3.311, df = 20;  p  < 0.001,  t =  − 5.808, df = 20; respectively) (Figs. 3, 4 and  5).