How much time does it take peritonitis to heal?

Hard to say!: Peritonitis is an infection within the abdominal cavity with manifestation of infection on the lining of the abdomen and the lining of the bowel and organs. Depending on the cause, the extent of the infection, the treatment, the state of health, and many other issues it can take as little as a couple of days to several weeks or more. Very hard to answer specifically. Let's say 3-14 days?

Variable: It depends on the cause of the peritonitis, if it is associated with peritoneal dialsis, it amy be a matter of a week or two on antibiotics with or without a change of catheter. If it is from a bowel leak, surgery has been done and IV antibiotics are given for a variable amount of time. This can be a serious problem and must be treated as such.