Anatomy and function of the lower digestive tract:

The gastro-intestinal tract begins with the mouth where the food is ground. It then reaches the stomach through the food pipe (esophagus). From the stomach, where the food is mixed with digestive juices (supplies from the stomach, liver, and pancreas), the food enters the small intestine, where most of the nutrients are absorbed into the blood to reach the body cells. The large intestine (colon) reclaims and maintains the water balance, and absorbs some vitamins, such as vitamin K. From the large intestine, the waste is stored in the rectum from where it goes out of the body through the anus. The imperforate anus is an abnormality with which some babies are born.

The function of the colon is to store the waste from the food that has been digested; reclaim and maintain the water balance, and absorb some vitamins, such as vitamin K.

Few babies are born without an opening for stool to pass from the large intestine (colon). This abnormality is called an imperforate anus. Immediately after birth, this defect is detected, as it is very obvious. There are several degrees of this congenital defect. In most hospitals, doctors will be able to determine what type of defect the child was born with and whether or not there are any associated malformations. It is very important to determine the presence of any associated defects during the newborn period in order to treat them early and avoid further complications.

There are two main types of ano-rectal malformations:

 Those that require an immediate operation, a by-pass within the first twenty-four hours – a colostomy (Opening of the large gut onto the abdominal wall), and,
 Those that do not require an immediate operation.

Other congenital abnormalities that can be absorbed with imperforate anus are:

 Defects in the baby’s back that affect the nervous system in the lower limbs
 Congenital abnormalities in the baby’s heart
 Abnormal connection between the baby’s wind and food pipes (tracheoesophageal fistula)
 Congenital narrowing of the food pipe
 Congenital abnormalities of the kidney
 Congenital abnormalities of the limbs

There are many different forms of imperforate anus. These are:

 The low form, in which the colon (large intestine) remains close to the skin. In this case, there may be a stenosis (narrowing) of the anus, or the anus may be missing altogether, with the large intestine ending in a blind pouch
 A low form, in which the colon is higher up in the pelvis and there is a fistula connecting the rectum and the urinary bladder, or the vagina
 A cloaca, where the rectum, vagina (in the female) and large intestine are joined into a single opening

Treatment
An imperforate anus usually requires immediate operation to open a passage for stool. Depending on the severity of the imperforate, it is either treated with a perineal opening at the site where the anus is normally located, or a colostomy (a surgical procedure that involves connecting a part of the large intestine/colon) onto the anterior abdominal wall, leaving the patient with an opening on the abdomen called a stoma. This opening is formed from the end of the large intestine drawn out through the incision and sutured to the skin. After the colostomy, feces leave the patient’s body through the stoma, and collect in a pouch attached to the patient’s abdomen which is changed when necessary.

The Final Outcome
With a high lesion, many children have problems controlling bowel function and must also become constipated. With a low lesion, children generally have good bowel control but may still become constipated.

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Copyright Liberian Observer

Observer Doctor
By:  Dr. Walter Brumskine

http://www.liberianobserver.com