TABLE 6. Two groups changes on anal canal diameter before and after surgery .

Variables	Control group	Observation group	t value	p value
Pre-operation	8.38±0.39	8.34±0.35	0.700	0.485
Post-operation	7.55±0.32	8.01±0.29	9.801	<0.0001
t value	15.074	6.689	/	/
p value	<0.0001	<0.0001	/	/