<p>Your peritoneum is the tissue that lines your abdominal wall and covers most of the organs in your abdomen. A liquid, peritoneal fluid, lubricates the surface of this tissue.</p> <p>Disorders of the peritoneum are not common. They include:</p><ul> <li>Peritonitis - an inflammation of the peritoneum</li> <li>Cancer</li> <li>Complications from peritoneal <a href="https://medlineplus.gov/dialysis.html">dialysis</a></li> </ul> <p>Your doctor may use imaging tests or lab tests to analyze the peritoneal fluid to diagnose the problem. Treatment of peritoneal disorders depends on the cause.</p>