You may also want to try a little vaseline an the anus. It'll keep them from cracking further when you do go and help them heal. Best of luck!
Anal fissure may occur when you pass hard or large stools during a bowel movement.
If an anal fissure doesn't heal, medical treatment or surgery can usually relieve discomfort.
Most anal fissures heal within a few weeks
I suggest taking a fiber supplement if you have hard or large stools.
An excellent product is Konsyl Fiber you can buy it at any drug store