Abdominal cavity, which includes the stomach, to perform kidney functions.

Q .This may sound like a crazy question, but is it possible to use your own stomach to take over for your kidneys when they aren’t working right?

This question isn’t as bizarre as it seems. It is possible to use the abdominal cavity, which includes the stomach, to perform kidney functions.

Kidneys are designed to remove waste and extra fluid from your blood. These organs contain millions of tiny blood vessels to handle this task. They also make hormones that keep your bones strong and your blood healthy.

If your kidneys aren’t working properly, unwanted substances in the blood can be removed through a process called dialysis. Most people who need dialysis can lead a reasonably normal life.

There are two types of dialysis: hemodialysis or peritoneal dialysis.

In hemodialysis, a patient is connected to an artificial kidney. This mechanical kidney — or dialyzer — filters the blood, and then it is returned to the patient. The treatment time typically lasts three to four hours. Most people suffering chronic kidney failure require hemodialysis three times a week. Hemodialysis can be done in a health-care facility or at home.

In peritoneal dialysis, the filter that is used is the peritoneum, the large, bloodrich membrane lining the abdomen and the organs within it. A fluid is sent into the abdominal cavity via a catheter inserted into the abdominal wall. This fluid (dialysate) is left in the cavity long enough to absorb blood wastes. Then the fluid is drained and replaced.

There are several kinds of peritoneal dialysis but two major ones are: Continuous Ambulatory Peritoneal Dialysis (CAPD) and Automated Peritoneal Dialysis (APD).

Continuous Ambulatory Peritoneal Dialysis (CAPD) is the only type of peritoneal dialysis that is done without machines. You do this yourself, usually four or five times a day at home and/or at work.

You put a bag of dialysate (about two quarts) into your peritoneal cavity through the catheter. The dialysate stays there for about four or five hours before it is drained back into the bag and thrown away. This is called an exchange.

You use a new bag of dialysate each time you do an exchange. While the dialysate is in your peritoneal cavity, you can go about your usual activities at work, at school or at home.

Automated Peritoneal Dialysis (APD) usually is done at home using a special machine called a cycler. This is similar to CAPD except that a number of cycles (exchanges) occur. Each cycle usually lasts 1-1/2 hours, and exchanges are done throughout the night while you sleep.

Dialysis is usually prescribed when kidney problems are responsible for the following: heart failure, abnormal brain function, inflammation of the sac around the heart, an overload of body fluid, high acid or potassium levels in the blood.

More than half of the people on long-term dialysis are 60 or older. Older people often adapt more easily than younger people to long-term dialysis. However, seniors are more likely to find the treatments tiring.

Fred Cicetti is a freelance writer who specializes in health. He has been writing professionally since 1963. Before he began freelancing, he was a reporter and columnist for three daily newspapers in New Jersey. If you would like to ask a question, write to fred@healthygeezer.com.