I have asked my father , mother and other relatives that for one time hard stool do they get anal fissure ??? They all told no anal fissure . But for my case only one time little hard stool after 2 to 3 years one time hard stool leads to anal fissure which is very very painful. So , it is not possible to eradicate the tendency of getting anal fissure for sudden or occasionally hard stool by any surgery or means ??? Lateral internal sphincterotomy was already done 5 years ago but still It has recurred 2 times by getting hard stool taking antibiotics for fever .