- Potential risks for participants: PIPAC may cause side-effects. The most frequent potential side-effects are pain, nausea, fever, wound infection, diarrhea, obstipation, and minor damages to the kidney, liver, and bone marrow. These side-effects are mostly very mild. Moreover, the risk of side-effects of PIPAC is thought to be lower than the risk of side-effects of chemotherapy through the veins. Severe side-effects of PIPAC are extremely rare. The most important are a bowel perforation or a bleeding during PIPAC. So far, these severe side-effects have not been observed during PIPAC in patients with peritoneal metastases of colorectal cancer.