an anal fissure is a small tear or crack in the lining of the anus. If you experience severe pain or bright red bleeding during or after bowel movements, you may have an anal fissure. The most common symptoms of anal fissures are a sharp pain when you poo, often followed by a deep burning pain that may last several hours bleeding when you poo most people notice a small amount of bright red blood either in their poo or on the toilet paper when to see a gp. An anal fissure is a break or tear in the skin of the anal canal. Anal fissures may be noticed by bright red anal bleeding on toilet paper and undergarments, or sometimes in the toilet. If acute they are painful after defecation, but with chronic fissures, pain intensity often reduces. Anal fissures usually extend from the anal opening and are usually located posteriorly in the midline, probably because of the relatively unsupported nature and poor perfusion of the anal wall in that location. An anal tear (fissure) causes pain around the back passage (anus). Anal fissure (fissures) is a very painful condition caused by trauma to the anus and anal canal, which then cuts or tears the anus and anal canal tissue. These tears can be caused by straining to have a bowel movement, hard stools, and chronic episodes of diarrhea. Symptoms include rectal bleeding, anal itching, and painful bowel movements. sitz baths, or hip baths, can promote healing of an anal fissure. By soaking the rectal area in a tub of warm water -- two or three times a day for 10 to 15 minutes -- you can clean the anus. Common causes of bleeding from the anus include constipation, anal fissures, and hemorrhoids.