My mom has kidney failure and is on peritoneal dialysis, and recently she has been vomiting a lot. She had the flu and we though that was the cause of the vomiting. She usually only vomits when there's an infection near where the tube is. But the doctor tested for infection and she doesn't have an infection, and the flu has been gone for several days. Can anyone tell me any possible problems that might be causing her to vomit?