0.5 or close to 1.0,suggesting marker retained many parts of the sigmoid colon and rectum,FOOC possibility.Normal group,constipation group colon 48,72 hour markers district retention contrast,have significant differences.TI as the STC's kinetic parameters can be used as the difference between STC and the simple and reliable indicators FOOC.17 cases in this group(accounting for 68%)FC children with TI in 48 h,72 h were 0.5,in line with the characteristics of FOOC.Conclusion The results of this study showed that colonic transit time checks can be more accurately reflect the normal function of colonic transit may be the evaluation of patients with functional constipation colonic transit weaken the seriousness of the correct and reasonable to carry out sub-type of clinical treatment of important guiding significance.