Anal fistula, or fistula-in-ano, is an abnormal connection between theepithelialised surface of the anal canal and (usually) the perianal skin. It is originate from the anal glands, which are located between the two layers of the anal sphincters and which drain into the anal canal. If the outlet of these glands becomes blocked, an abscess can form which can eventually point to the skin surface. The tract formed by this process is the fistula.
An anal fissure or rectal 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, sometimes in the toilet. If acute they may cause pain after defecation but with chronic fissures pain intensity is often less. 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. Fissure depth may be superficial or sometimes down to the underlying sphincter muscle.
Haemorrhoids are commonly known as piles. They are caused by abnormal dilatation and enlargement of the blood vessels in and around the anus.Symptoms are bright red rectal bleeding , Pain, Itching, Lump in anus andCauses are constipation, Heavy lifting resulting in raised pressure inside the abdomen, Pregnancy, Obesity or being overweight.
Pilonidal sinus (PNS) is a small cyst or abscess that occurs in the cleft at the top of the buttocks. It can cause severe pain and often becomes infected. If it becomes infected, it may exude pus and blood and emit a foul smell. A pilonidal sinus is a condition that mostly affects men and is common in young adults.
Rectal prolapse may occur without any symptoms, but depending upon the nature of the prolapse there may be mucous discharge (mucus coming from the anus), rectal bleeding, degrees of fecal incontinence and obstructed defecation symptoms. Rectal walls have prolapsed to a degree where they protrude out the anus and are visible outside the body. However, most researchers agree that there are 3 to 5 different types of rectal prolapse, depending on if the prolapsed section is visible externally, and if the full or only partial thickness of the rectal wall is involved.