By Sister Lesley Everingham, CNC Royal Prince Alfred Hospital

A hernia is the abnormal protrusion of an organ or part of an organ through an opening/rupture in the cavity wall in which it is contained.
In the case of a parastomal hernia, the bowel or small intestine protrudes through a defect in the abdominal wall resulting in a bulge behind the stoma.
A parastomal hernia is a common complication and in most cases will form within the first few years after the stoma has been constructed.

What Causes a Hernia?

A weakness in the abdominal wall would be a major cause for developing a parastomal hernia. This weakness may be a result of the rectus muscle, which is the muscle that extends down the front of our abdomen and normally provides support to our abdominal wall, having been severed. This muscle would have been cut through, when the surgeon brought the bowel out onto the abdomen to construct the stoma. If the stoma is not brought out through the rectus muscle there is a higher incidence of herniation and stomal prolapse.

When there is a weakness in the muscle, heavy lifting, coughing, obesity and constipation may cause strain, which results in further rupturing. Care should always be taken when exercising or lifting, but especially so in the first few months after surgery when the muscle fibres are trying to heal together. Steps should be taken to avoid/reduce obesity and constipation. Coughs should be treated early and the abdomen supported when coughing.

Repeated abdominal surgery may severely weaken the abdominal muscle increasing the incidence of hernias. There appears a higher incidence of parastomal hernias in those with a colostomy than with an ileostomy.

Management of a Parastomal Hernia:

In many cases, a parastomal hernia may result in only a slight bulge that does not cause any management problems. However, as the bulge gets larger, apart from becoming obvious under clothing, the pressure of the bowel protruding through the abdominal wall will cause discomfort and can sometimes make it difficult to walk.

Some colostomates with parastomal hernias will complain of passing frequent small motions and those who irrigate their colostomy may experience a delay in the fluid returning. It is usually recommended that these people should discontinue irrigation due to the increase in intra abdominal pressure, as a result of the colon filling with the water, thus putting more pressure on the already weakened abdominal wall.

An abdominal binder, lycra cummerbund or corset is ideal to help support the abdomen. Previously, it was felt necessary that a hole should be made in the binder for the bag to be brought through, however we now find this may in fact worsen the condition and is therefore not recommended.

Most people will find the hernia is smaller or non existent first thing in the morning as lying flat has allowed the bowel to drop back into the abdomen and increases during the day due to increased activity. Because of this, an abdominal support should always be applied when lying flat, as you are aiming to prevent the bowel from herniating.

Difficulty may be experienced with the adhesive of the stoma appliance moulding over the bulge, thus resulting in leakages. It would be necessary to experiment with different appliances to find the one that will mould the best. As the bulge enlarges, the stoma itself may also become larger; therefore, the opening in the appliance will need to be adjusted accordingly.

If there is a large amount of bowel trying to herniate through a smallish defect or rupture in the abdominal wall, strangulation of the bowel may result. Strangulation will be identified by the stoma becoming a very dark red, purple or even black. If this happens, urgent medical attention should be sought.

For problematic hernias surgery may be necessary. A laparotomy would be performed and the rupture repaired. In some cases, the stoma may be resited to the opposite side of the abdomen. Occasionally, Marlex mesh will be used to strengthen the repair, however there can be an increased risk of infection with this procedure.

Despite surgery hernias can re-occur therefore careful management and appropriate support appliances are often the best course of action.