What Is Peritoneal Washing?

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Peritoneal washing (abdominopelvic washing) is a procedure used to diagnose whether certain types of cancer are present in the peritoneal cavity—the space between the membranes that line the abdomen.

It is not performed on its own but during surgeries to remove tumors or see if tumors are present in the body. Peritoneal washing is most commonly performed during ovarian cancer surgeries but is also used in endometrial, pancreatic, and gastric cancer surgeries. The results of this procedure help diagnose a patient with cancer, determine how far the cancer has progressed, and develop a treatment plan.

This article explains how peritoneal washing works, its uses, limits, and risks.

Doctor with a patient

wera Rodsawang / Getty Images

What Is the Peritoneal Cavity?

The peritoneum is a thin membrane that lines the abdominal cavity. It protects and supports organs in the abdomen and pelvis, including the stomach, intestines, and liver. The peritoneum is made of two layers, and the peritoneal cavity is the space between these two layers. The peritoneal cavity doesn’t contain organs but contains small amounts of fluid.


Peritoneal washings are typically performed when healthcare providers suspect cancer may be present. It is most commonly used during ovarian cancer surgery.

The results from peritoneal washing can determine the type of ovarian tumor a patient has and are part of the guidelines practitioners use when diagnosing the stage of cancer. A cancer's stage indicates how large the tumor is and if the cancer has spread in the body. Peritoneal washing can also help determine the prognosis for certain gastric and pancreatic cancers.

In some cases, peritoneal washing is used during "second-look surgery." This surgery is performed once cancer is diagnosed to see how far it has spread or after treatment to see if any cancer cells remain.


Results from specimens obtained during peritoneal washing can sometimes be challenging to interpret. Certain conditions, such as endometriosis, can make cells appear cancerous even though they are benign (not cancerous). Chemotherapy or radiation therapy can also cause cells to appear cancerous even if they are not.

The use of peritoneal washing for determining the prognosis and treatment for endometrial cancer, especially in its early stages, is debated in the medical community.

How It Works

Peritoneal washing is performed during surgery to look for cancer or remove tumors. It is performed with the patient under general anesthesia in a hospital setting and before other surgical procedures. This is to make sure the sample is kept clean and away from any other tumors that might be found or removed during the surgery.

The peritoneal cavity is bathed in a sterile saline or saltwater solution during the procedure. The solution and cells from the cavity are then removed and sent to a lab to be tested.

How long the procedure will take and the amount of time needed to recover depends on the type and extent of the overall surgery being done.

Cancer Surgery Approaches

There are different approaches to cancer surgery. They include:

  • Open surgery involves a long incision and a longer time to heal than other types.
  • Laparoscopic surgery uses small incisions to place surgical instruments and a camera. The surgeon performs the procedure using video. This method usually has faster healing than open surgery.
  • Robotic-assisted surgery uses small instruments guided by a surgeon controlling a robotic device. This approach is also faster in healing than open surgery.

Who Does It

Peritoneal washing is performed by a surgical team that typically includes oncologists and/or surgical oncologists and an anesthesiologist (a doctor trained to administer anesthesia).


After the procedure, the solution is analyzed for cancer cells (peritoneal cytology). If the peritoneal cytology is positive, then cancer cells are present. If it is negative, that means cancer cells have not been found. The results also typically contain more detailed information about the types of cells found.

Once the lab results are in, your healthcare provider will discuss them with you and any other surgical findings and treatments that may be required.

What Is Cytology?

Cytology means examining a single cell type. Cytology is primarily used to diagnose cancer and is used for Pap smears, screening for fetal abnormalities, or diagnosing infections. Cells are gathered for cytology by collecting bodily fluids, scraping or brushing the surface of a tissue, or removing them with a fine needle.

Risks and Contraindications

Peritoneal washing does not cause any side effects. However, it is done under general anesthesia during cancer surgery, so you should discuss your risks with your healthcare provider. These risks will vary depending on your health and the type of surgery you have.

You also may have side effects from general anesthesia. These side effects are temporary and should begin to subside within 24 hours. They include:

  • Nausea
  • Sleepiness
  • Dizziness
  • Sore throat (from the breathing tube placed during surgery)
  • Chills


Peritoneal washing is performed during surgery for certain types of cancer to help determine if cancer is present or has spread to the peritoneal cavity. It is most commonly performed as part of ovarian cancer surgery but can also be done during surgeries for endometrial, prostate, and gastric cancers. During the procedure, the peritoneal cavity is washed with a sterile solution. The solution and cells are removed and examined for cancer. The results help healthcare providers diagnose cancer, determine the stage of cancer, and develop treatment plans.

A Word From Verywell

Having surgery for cancer can be a source of anxiety. It’s important to know that when your healthcare team has recommended surgery, it’s so they can make sure you get the most appropriate treatment for the best chance of recovery. Don’t be afraid to ask your healthcare providers questions, and write down what they say to remember later. If you feel you need support, ask your healthcare provider about resources for groups that can assist you in meeting your needs, whether they are physical, mental, or emotional.

10 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  5. De Andrade JP, Mezhir JJ. The critical role of peritoneal cytology in the staging of gastric cancer: an evidence-based review. J Surg Oncol. 2014;110(3):291-297. doi:10.1002/jso.23632

  6. Blok F, Roes EM, van Leenders GJLH, van Beekhuizen HJ. The lack of clinical value of peritoneal washing cytology in high risk patients undergoing risk-reducing salpingo-oophorectomy: a retrospective study and review. BMC Cancer. 2016;16(1):18. doi:10.1186/s12885-015-2011-5

  7. Lili Wang, Lei Li, Ming Wu, Jinghe Lang, The prognostic role of peritoneal cytology in stage IA endometrial endometrioid carcinomas. Current Problems in Cancer. 2020;44(2):100514. doi:10.1016/j.currproblcancer.2019.100514

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  9. John Hopkins Medicine. Cytology.

  10. Johns Hopkins Medicine. Anesthesia options, risks, and side effects.

By Cathy Nelson
Cathy Nelson has worked as a writer and editor covering health and wellness for more than two decades. Her work has appeared in print and online in numerous outlets, including the Detroit Free Press and The Detroit News.