Thanks for your query.
has occured in the anal passage. This is know as anal fissure
and is very painful while passing stools. The stools will appear steaked with blood on the side of the injury. It is suggested you get her examined by a surgeon who shall prescribe and explain appropriate medicine for application along with stool softners and sitz bath. If the pain does not get relieved by sitz bath pain killers will be advised.
Wishing your wife an early recovery.