👉 Antiperistasis is a condition in which the peritoneum (the lining of the abdomen) is unable to form a barrier between the abdominal cavity and the peritoneal cavity. This leads to the formation of an intestinal wall that is less permeable than normal, making it more susceptible to infection and inflammation. In patients with antiperistasis, the peritoneal lining may be thickened or even completely absent, leading to a condition known as ileus (irritable bowel syndrome).