Many anorectal problems, including fissures, fistulae, abscesses, or irritation and itching have similar symptoms and are incorrectly referred to as haemorrhoids. Haemorrhoids usually are not dangerous or life threatening. Rarely, a patient can have bleeding so severe, that severe anaemia or death may occur.

   Internal hemorrhoids cannot cause cutaneous pain, because they are above the dentate line and are not innervated by cutaneous nerves. However, they can bleed, prolapse, and, as a result of the deposition of an irritant on to the sensitive perianal skin, cause perianal itching and irritation. Internal hemorrhoids can produce perianal pain by prolapsing and causing spasm of the sphincter complex around the haemorrhoids. This spasm results in discomfort while the prolapsed haemorrhoids are exposed. This muscle discomfort is relieved with reduction.

   Internal haemorrhoids can also cause acute pain when incarcerated and strangulated. Again, the pain is related to the sphincter complex spasm. Strangulation with necrosis may cause more deep discomfort. When these catastrophic events occur, the sphincter spasm often causes concomitant external thrombosis. External thrombosis causes acute cutaneous pain. This consternation of symptoms is referred to as acute haemorrhoidal crisis. It usually requires emergency treatment.
Internal haemorrhoids can deposit mucus on to the perianal tissue with prolapse. This mucus with microscopic stool contents can cause a localized dermatitis, which is called pruritus ani.

   External haemorrhoids cause symptoms in two ways. First, acute thrombosis of the underlying external haemorrhoidal vein can occur. Acute thrombosis is usually related to a specific event, such as physical exertion, straining with constipation, a bout of diarrhoea, or a change in diet. These are acute, painful events. Pain results from rapid distension of innervated skin by the clot and surrounding oedema. The pain lasts 7-14 days and resolves with resolution of the thrombosis. With this resolution, the stretched anoderm persists as excess skin or skin tags. External thromboses occasionally erode the overlying skin and cause bleeding. Recurrence occurs approximately 40-50% of the time, at the same site because the underlying damaged vein remains there.

   External haemorrhoids can also cause hygiene difficulties, with the excess, redundant skin left after an acute thrombosis (skin tags) being accountable for these problems. External haemorrhoidal veins found under the perianal skin obviously cannot cause hygiene problems; however, excess skin in the perianal area can mechanically interfere with cleansing.

An anal fissure can be diagnosed by naked eye inspection. Closer inspection will frequently reveal a tag or sentinel pile. After gentle separation of the skin of the anal verge, the ulcer usually posterior can be seen. Frequently the fibers of the internal anal sphincter muscle can be seen at the base of this punched-out ulcer. A colonoscope or sigmoidoscope exam might be useful to rule out abscesses, colitis, and other causes of rectal bleeding.A fissure should be distinguished from an ulcer caused by Crohn’s disease, leukemia, or malignant tumors, because it is not shaggy, large or indolent. Fissures are seldom multiple. A biopsy can help to determine the diagnosis.

   An ano rectal abscess mimics the Haemorrhoids , but they can be distinguished by its location. Pain swelling occurs near by anus. Most fistulas begin as anorectal abscesses. When the abscess opens spontaneously or has been opened surgically, a fistula may occur. Other causes of fistulas include tuberculosis, cancer, and inflammatory bowel disease. Fistulas may occur singly or in multiples.