RESUMEN
Objective To evaluate the changes of rectal morphology and its clinical value in internal rectal prolapse.Methods The rectal morphology of internal rectal prolapse in thirty-one patients with functional constipation and ten normal control subjects was analysed with defecography.The data were analysed with Mann-Whitney Unonparametric test and Fisher's exact test.Results 23 cases and 2 cases with rectal intussusception in patients group and control group respectively were found.Fisher's exact test was P=0.007.In patients group and control group,the thicknesses of anterior intussusception were(13.51 ±9.42)mm and(3.68±2.34)mm,and posterior intussusception were(5.36±3.92)mm and(2.82±0.99)mm respectively;the intussuscipiens diameters were (37.19±11.79)mm and(25.32±9.25)mm,the intussusceptum lumen diameters were(14.91±4.74)mm and(19.73±6.36)mm,the ratio of intussuscipiens diameters and lumen diameters were 2.82±1.64 and 1.28±0.12,the maximum rectal diameter were(48.97±9.55)mm and(39.84±8.45)mm at rest state.There were significant differences between patients group and control group in above varied values(P＜0.05).Conclusion Defecography can differentiate whole thickness rectal intussusception from rectal mucosal prolapse,which provides the scientific basis for choosing the reasonable treatment.However,caution is required when selecting patients for treatment interventions based on defecography.