Yes, that's every bit as bad as it sounds:
An anal fissure is an unnatural crack or tear in the anus skin. As a fissure, these tiny tears may show as bright red rectal bleeding and cause severe periodic pain after defecation. [...] Most anal fissures are caused by stretching of the anal mucosa beyond its capability. Various causes of this fissure include:On three: OW. Poor Kaz. This is almost worse than Felix Pie's twisted testicle. Almost.
* Straining to defecate, especially if the stool is hard and dry
* Severe and chronic constipation
* Severe and chronic diarrhea
* Crohn's disease and Ulcerative colitis
* Tight sphincter muscles
* Anal intercourse