Definition An anal fissure is synonymous with fissure in ano. It is an elongated ulcer in the long axis of the lower anal canal. It is one of the most painful conditions resulting in a lot of discomfort and embarrassment to the patient.
Symptoms This condition is more common in women and generally occurs during the meridian of life. Pain Sharp, agonizing pain during defecation and great integrity, may last for an hour or more. The patient is comfortable until the next defecation, periods of remission occur for days or weeks. Constipation Due to severe pain during defecation, the patient tends to become constipated. He has to take some laxative to move his bowels. Bleeding This is painful, occurs at the end of defecation. It does not cause anemia. Discharge A slight discharge accompanies fully established cases. This causes itching.
Causes 1.Chronic constipation: Due to overeating, eating a diet that is less in fiber (in a non–vegetarian diet) leads to constipation. Hard stools cause damage to anal epithelium, leading to fissures. 2.An incorrectly performed operation causes hemorrhoids in which much skin is removed. This results in anal stenosis and tearing of the scar when hard stools are passed. 3.Inflammatory bowel diseases, particularly Cohn’s disease. 4.Sexually transmitted diseases.
Pathophysiology with Anatomical Considerations The commonest site of the anal fissure is posterior midline. The posterior wall of the rectum is curved forwards from the hollow of the sacrum to join the anal canal, which then turns sharply backwards. During defecation the pressure of a hard fecal mass is mainly on the posterior anal tissues, in which event the overlying epithelium is greatly stretched and, being relatively unsupported by muscle, is placed in a vulnerable position when a fecal mass is being expelled. So, in 90% of the cases, the fissure is situated in the midline in the posterior.
The next common situation is the midline in the anterior. This is much more common in females, particularly in those who have borne children. This can be explained by the lack of support of the anal mucus membrane by a damaged pelvic floor and an attenuated perineal body. The upper internal end of the fissure stops at the dentate line. Since the fissure occurs in the sensitive epithelium of the lower half and the anal canal, pain is the most prominent symptom. Every patient of anal fissure lands into a vicious cycle.