Anal fissure is a common condition, particularly affecting younger age group when a crack in the anal skin refuses to heal and becomes a deep groove.
This causes spasm of the muscles around which further causes delay in the healing. It then becomes a vicious cycle...
Treatment depends on the chronicity of the problem. Avoiding straining or constipation and taking a high fibre diet with some special topical ointments can lead to resolution of symptoms in some. Surgery is required in some cases where a small cut is made into the muscle to help the fissure get blood supply and heal.
Anal fistula is a different entity than a fissure. It is essentially a tunnel formed from infection in the muscle space around the anus. An external opening of the tunnel lies around the anus on the skin discharging pus/blood; and the internal opening lies inside the anus feeding the infection in the tunnel.
Treatment can be challenging and sometimes a colonoscopy is required to rule out Crohn's disease. Surgical treatment is usually required. It may involve laying open of the tract, or sometimes putting a thread in the tract and laying it open in the next stage.
Anal warts are little skin projection within the anal canal or around the anus which sometimes can cause discomfort or wetness. They can also sometimes undergo a pre-cancerous change called AIN (Anal Intra-epithelial Neoplasia) and regular check-ups are required. They can be removed with surgery.
Anal skin tags are simple skin folds around anus, which can cause discomfort or difficulty in wiping causing poor hygiene. They can be simply removed with electrocautery. Often they are extensions of interno-external haemorrhoids, when a haemorrhoidectomy is required.
Anal polyps are usually benign polyps which can often form when an anal fissure has been present for some time (chronic). These types of polyps are called fibro epithelial polyps (FEP), and can be simply removed by minor surgery
Please see Haemorrhoids page