To investigate the characteristics of anorectal motility and rectal perception in female outlet obstruction constipation(OOC) patients.

The data of anorectal motility and rectal perception of 53 OOC patients and 60 healthy volunteers who admitted to the constipation platform of Nanjing Hospital of Traditional Chinese Medicine from January 2018 to December 2018 were retrospectively analyzed.

The mean anal resting pressure of 53 patients was higher than the normal reference value (t=4.985, P<0.01). When the average maximum systolic blood pressure is lower than the normal reference value (t=7.555, P<0.01). In rectal bowel pressure, the average bowel pressure of all patients was also lower than the normal reference value (t=4.297, P<0.01); Anal sphincter length increased in OOC patients compared with healthy women (t=4.825, P<0.01); The differences of anal repose pressure between OOC patients with different complications and normal reference values were statistically significant (t_prolapse =5.257, t_{perineal decline} =6.091, t_{intusculation} =4.23; P<0.05). The overall mean maximum systolic blood pressure was lower than the normal reference value, and the difference was statistically significant between all types of patients (t_{anterior process} =6.277, t_{perineal decline}=5.306, t_{intusculation}=3.293; P<0.05), all types of patients showed low rectal pressure, but only the rectal prolapse and perineal decline were statistically significant compared with healthy patients (t_prolapse =3.313, t_{perineal decline} =4.637; P<0.05); Both the defecation threshold and the mean defecation threshold of the patients were higher than the normal reference value, and the differences were statistically significant (t=2.818, P<0.05). Although the mean initial threshold of 53 patients was higher than the normal reference value, the difference was not statistically significant (P>0.05). The difference between the maximum tolerance and the normal reference value was also not statistically significant (P>0.05). There was no significant difference between the initial threshold value and the normal reference value in patients with constipation of the 4 complications (P>0.05).

Outlet Obstruction Constipation dynamic characteristics are mainly manifested as high anorectal resting pressure, low systolic pressure, and low rectal sensitivity, which indicates that the contraction and coordination dysfunction of the external anal sphincter and pelvic floor muscles, decreased rectal sensitivity and slow response to volume stimulation may be an important cause of functional constipation.