MACE - Malone Antegrade Continence Enema

The Malone Antegrade Continence Enema or MACE has been used for decades in children and adults who have difficulty either passing a bowel movement or who have chronic leakage of stool (accidents). You may also hear the procedure referred to as a Malone procedure - after the physician who popularized the method.

How does the MACE work?

The MACE works by emptying the colon of stool using water (similar to an enema) which is infused through a catheter (tube) in the colon, rather than from below. The water in the colon acts like a river that pushes the stool downstream. A MACE is particularly useful for people who have poor rectal tone and cannot hold in the contents of an enema from below.

Will the MACE work?

Stool accidents may still occur, but usually only during the initial phase while we figure out the correct amount of fluid and the timing of the water instillations. By adjusting the amount of irrigation, and the timing, you should not have another bowel movement until the next time the enema is administered. This is usually done once daily.

What is the typical water instillation schedule?

A catheter will typically be left through the ostomy for the first 2 to 3 weeks after surgery. Starting 2 to 4 days after surgery, you will be instructed to flush it daily with 100 ml of tap water or saline. After this time period, your physician will typically remove the catheter and have you begin to place a catheter into the stoma (opening) daily and flush with water or saline.

Amounts will vary, depending on your size, from 500 ml to 1000 ml. Most irrigations occur once daily; however, some people will need two irrigations a day. Irrigations are given using a gravity flow bag that attaches to your catheter.

In the first two weeks, irrigations are given with a 60-ml syringe, which will be provided to you prior to discharge from the hospital. Typically, once a day, instill 50 cc's of luke warm (body temperature) tap water or normal saline. Use a 60cc syringe to plunger the water slowly into the MACE catheter. It is recommended that you sit on the toilet for the procedure. There may be no stool results with the first few water instillations you do.

Enemas will be increased every fourth day by 50cc's. Your doctor or urology nurse will give the schedule to you.

Once the amount has reached 200cc's, you may use an enema set for easier infusion. You will be instructed on how to prime the tubing (flush it with water) so air is not infused into the bowel, which can cause cramping. The tubing has a roller clamp that regulates how fast the water is infused. The height of the bag will also determine how quickly the water is infused. If cramping occurs, slow down the infusion and make sure the water is not cold.

The amount of fluid needed to get a good result varies from patient to patient. The amount of fluid typically needed for a good result ranges from 250cc's to 1000cc's. Stool accidents can occur while adjusting the enema amounts.

When should you follow- up after the surgery?

You should be seen in the office 2-3- weeks after surgery. At this time, the MACE catheter will be removed and you will be instructed on how to insert and remove the catheter yourself. Regardless of how often you perform the enema, you will need to insert the catheter through the MACE stoma twice a day. The first passage of the catheter per day will be to irrigate and flush out the bowels. The second passage of the catheter in the evening will be only at the skin level and is done to help keep the stoma open and from scarring.

How do you perform the water instillations into the MACE?

  1. Pass the catheter 2-4 inches in the stoma.
  2. Infuse the fluid.
  3. Remove the catheter
  4. Clean the area around the stoma with mild soap and water, gently pat dry.
  5. The catheter may be re-used. Wash the catheter with soap and water and allow it to air dry.

Diagram of Malone Antegrade Continence Enema

When should you use the MACE?

It is best to use the MACE the same time every day. Pick a time that is not rushed for you. You will need approximately 20-45 minutes. In the beginning, the irrigations may seem difficult to give and to fit into your daily routine. However, as you become more comfortable with the process it will become a fairly straightforward routine. You may still have to alter your diet or take stool softener medication.

What if the constipation is not improving or I am still soiling?

Adding 30 ml of mineral oil into the MACE 20 minutes before each irrigation may be helpful. Other additives that can be helpful are Miralax 17gm (a capful) in 240cc water 20 minutes before irrigation or 60 cc of glycerin in 60 cc water.

What symptoms after surgery are concerning?

  • Fever > 100.5 degrees F
  • Increasing tenderness at the surgical site
  • Increasing swelling or redness or tenderness around the incision or stoma
  • Any unusual drainage or odor from the incision or stoma
  • Nausea, vomiting, diarrhea, or constipation which is not improving