Cremaffin plus and other such laxative syrups usually create dependence, such as in your case. The reason you have hard stools without Cremaffin is probably insufficient water intake and fibre intake. Please drink atleast 3L water per day, and have enough fibre in your diet. For your fissure, if it keeps recurring everytime you have a normal to hard stool, it is better to find a permanent solution. Today, Laser surgery for anal fissure is a very good option, with much less pain and quick recovery.