Objective: To investigate the effect of modified Bazhengsan on time of urination and ability restoration of self urination in patients with damp-heat pouring downward syndrome urinary retention after anal fistula surgery

and explore its action mechanism. Method: The 106 patients with urinary retention after anal fistula surgery were randomly divided into 2 groups

53 cases in control group and 53 cases in treatment group.Patients in two groups were given with basic treatment such as listening to the sound of water induction

psychological counseling and bladder area massage therapy.Then patients in control group received neostigmine bromide by oral administration

and patients in treatment group received modified Bazhengsan.Urinary dynamics were detected; bladder function and the main traditional Chinese medicine (TCM) symptom scores were evaluated; urination situation was recorded and compared after the treatment. Result: Urodynamic parameters such as maximum urination quantity (Q-max) and detrusor pressure at maximum urine rate Pdet-Q-max were increased in both groups after treatment (P<0.01); maximum cysto-metric capacity (VMCC) and postvoiding residual volume (PRV) were decreased (P<0.01); bladder detrusor dysfunction

low bladder compliance and incidence of bladder sensory were decreased (P<0.05); acraturesis

abdominal bulge and languid symptom scores were decreased in both groups after treatment (P<0.01).As compared with control group after treatment

levels of Q-max and Pdet-Q-max were higher (P<0.01); VMCC

PVR levels were lower (P<0.01); the incidences of bladder detrusor dysfunction

bladder compliance and bladder sensory loss were lower (P<0.05); self urination

completely unobstructed urination

defecation and eating time was shorter (P<0.01); acraturesis

abdominal bulge and fatigue symptom scores were lower (P<0.01); and the total efficiency was higher in treatment group (P<0.05). Conclusion: Modified Bazhengsan can promote the bladder urination

reduce the residual urine volume

shorten the self urination time

and improve the ability restoration of automatic micturition

so it can be used to effectively treat damp-heat pouring downward syndrome postoperative urinary retention.