Anal Fissure
Anal fissure is a split in the skin of the anus. The passage of a hard stool commonly causes anal fissures; however, a history of constipation preceding the onset of an anal fissure is obtained in only one of four cases, and diarrhea is a predisposing factor in 4 to 7% of patients. Fissures are usually located in the anterior or posterior midline. Other processes, for example infectious or inflammatory, should be entertained when the fissure is positioned laterally. Blood is often seen on the surface of the stool, on the toilet tissue, or even dripping from the anus. There may be severe anal pain associated with the fissure, especially during defecation.