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Paracentesis (abdominal tap)

This information will help you prepare for your paracentesis at Memorial Sloan Kettering Cancer Center (MSKCC).

A paracentesis, also called an abdominal tap, is a procedure to remove fluid from the stomach. When fluid collects in the stomach it is called ascites. Ascites can create pain in the stomach.

Ascites may be caused by:

  • Cancer
  • An infection
  • Inflammation
  • An abdominal injury

Ascites is also caused by liver cirrhosis. Cirrhosis is a liver disease that causes scarring of the liver.

A paracentesis removes fluid by placing a catheter (small flexible tube) into the wall of your stomach. The fluid may be sent to a lab and studied to find the cause of the fluid buildup.

Before Your Procedure

For your safety

At MSKCC, we want to keep you safe during your procedure. Put a check mark next to any statement that applies to you. Put a question mark if you are not sure. Be sure to go over this list with your doctor or nurse:

  • I take a blood thinner, such as heparin, warfarin (Coumadin®), clopidogrel (Plavix®), or tinzaparin (Innohep®)
  • I take any prescription medications
  • I take any over-the-counter medications, herbs, vitamins, minerals, or natural or home remedies
  • I have a pacemaker or other heart device
  • I have sleep apnea
  • I have had a problem with anesthesia (medicine to make you sleep during surgery)
  • I have allergies, including latex
  • I am not willing to receive a blood transfusion
  • I drink alcohol
  • I smoke
  • I use recreational drugs
  • I am or might be pregnant


Before your procedure you may have tests, including an ultrasound to locate the fluid in your stomach, blood tests, and any other tests necessary to plan your care.

A nurse may place an intravenous (IV) catheter into a vein, usually in your hand or arm. You will receive liquids through the IV.


Your doctor or nurse will talk to you about what you can and can't eat before your procedure.

Your Procedure

After changing into a hospital gown, you will be brought into the procedure room and helped onto an exam table. You will be attached to equipment to monitor your heart, breathing, and blood pressure. A member of our clinical team will help position you onto your back. Your stomach will be cleaned. A local anesthetic will be injected in the area where your doctor will be working.

Using a needle, a catheter will be put into your stomach. The catheter is connected to a bottle by a small tube. The fluid from your stomach will be drained through the catheter and into the bottle. It is important that you try not to move while the catheter is in place. Once enough fluid has been drained, the catheter will be removed and a small bandage will be placed over the punctured area.

After Your Procedure

  • After your procedure, get up slowly. Tell your doctor or nurse if you feel dizzy or lightheaded.
  • You may have some discomfort. Talk to your doctor or nurse about taking pain medication.
  • It is normal for a small amount of fluid to leak from the puncture site. Your doctor or nurse will give you bandages to protect your clothing in case this happens.

At home

  • Do not remove your bandage for 24 hours.
  • You can start showering 24 hours after your procedure. Remove the bandage and wash the injection area with soap and water. You may want to place a clean bandage over the area if there is any drainage.
  • Unless your nurse or doctor tells you not to, you may go back to your normal activities after your procedure.

Signs and Symptoms of Infection

Call your doctor or nurse if you have any of the following signs or symptoms of infection:

  • Redness at the puncture site
  • Increased pain in your stomach
  • A temperature of 100.4° (38.0°) or higher
  • Shaking chills
  • Shortness of breath
  • A lot of leakage from your puncture site