QS Study

Some Clinical Conditions associated with Anal Canal

Anal Canal is the terminal part of the large intestine, situated below the levels of the pelvic diaphragm. It is the last spot where stools pass through before finally exiting the body. It serves to lubricate and transmit fecal matter as it passes from the rectum to outside the body.

Clinical conditions associated with anal canal –

(1) Anal fissure

An anal fissure is a small tear in the thin, moist tissue (mucosa) that lines the anus. It is a small cut or tears in the lining of the anus. An anal fissure may happen when you pass hard or large stools during a bowel movement.

Symptoms – Signs and symptoms of an anal fissure include:

  • Sharp pain in the anal area during bowel movements
  • Pain after bowel movements that can last up to several hours
  • Bright red blood on the stool or toilet paper after a bowel movement
  • Burning or itching in the anal area
  • A visible crack in the skin around the anus.

Fig: Anal fissure


Common causes of an anal fissure include:

  • Passing large or hard stools
  • Constipation and straining during bowel movements
  • Chronic diarrhea
  • Childbirth

(2) Fistula in Ano

An anal fistula is a tunnel that runs from inside the anus, the hole your body uses to get rid of solid waste to somewhere in the skin around it. A fistula is a small tunnel that connects the infected gland inside the anus to an opening on the skin around the anus. The treatment for an anal fistula is surgery.

Symptoms – The following may be symptoms or signs of an anal fistula:

  • Pain and swelling around the anus.
  • Pain with bowel movements.
  • Irritation of the skin around the anus due to persistent drainage.

Fig: Fistula in Ano

Causes – Most fistulas result from an anal abscess. A small number of fistulas may less regularly be caused by other procedures such as Crohn’s disease, sexually transmitted diseases, trauma, tuberculosis, cancer, or diverticulitis.

(3) Piles (Haemorrhoids)

Piles (haemorrhoids) are enlarged blood vessels that you can get inside or around your anus. These are the dilated veins occurring in relation to the anus. They are inflamed and swollen collections of tissue in the anal area.


(a) Internal haemorrhoids –

  • Primary haemorrhoids,
  • Secondary haemorrhoids

(b) External haemorrhoids

(c) Intero external haemorrhoids.

Fig: Piles (Haemorrhoids)


Piles don’t always cause pain or other symptoms, but if you do have symptoms, they might include:

  • bleeding after passing a stool – the blood is usually bright red,
  • a lump in or around your anus
  • a mucus discharge after passing a stool
  • pain and discomfort after you go to the toilet
  • soreness, redness and swelling around your anus.

Causes – The exact cause of haemorrhoids is unclear, they are caused by increased pressure in the lower rectum.