Clinical research of anal canal resting pressure and transient anal sphincter relaxations

Objective To investigate the laws of transient anal sphincter relaxations (TASRs) appearing in resting state, and its relationship with anal resting pressure.To explore the pathophysiological significance of TASRs and how to complete anorectal manometry accurately in this situation. Methods From January 1 to October 31 in 2015, 33 constipated patients, 13 anal moist and pruritus ani patients, 13 healthy volunteers received anorectal manometry, detection time of anal resting pressure were prolonged to 15min, all manometry data were analyzed. Results Within 15min TASRs appeared in all three groups (10/13, 19/33, 11/13) and the proportion appeared no difference (P>0.05); When resting pressure above 60mmHg TASRs were more prone to appear (39/41). In the two groups with and without TASRs, there were no difference between anal length (2.71 ± 0.89 vs 2.32 ± 1.05) and first sensory capacity (51.8 ± 32.52 vs 63.0 ± 36.64) (P>0.05), but the differences were significant between depth of RAIR inhibition (54.28 ± 16.81 vs 40.46 ± 10.68) (P<0.05). Conclusions TASRs are very common and make ARP in a range of a fluctuation, we recommend recording ARP by a range value and at different time different manometry carried. TASRs and RAIR are likely homogeneous, mostly TASRs are normal physiological phenomenon, few deep TASRs may have pathological significance, and some of which can be perceived. Key words: Anal canal; Rectum; Anal canal resting pressure; Transient anal sphincter relaxations