What is a common symptom of peritonitis?

Nausea and vomiting are common symptoms of peritonitis due to the inflammation of the peritoneum, which can occur as a result of infections, perforations in the gastrointestinal tract, or other abdominal conditions. When the peritoneum becomes inflamed, it often leads to gastrointestinal disturbances, including nausea and an inability to tolerate food, which can result in vomiting.

This symptom is part of the body's response to inflammation and infection, as the digestive system often slows down or stops functioning optimally. This reaction can be compounded by the body’s systemic inflammatory response to infection, making nausea prevalent among those who are experiencing peritonitis.

In contrast, other options relate to symptoms that are not typically associated with peritonitis. Lower back pain may suggest other issues, such as musculoskeletal problems. Increased appetite is counterintuitive in the context of an inflammatory condition like peritonitis, where nausea would usually suppress appetite. A decreased heart rate is not characteristic of peritonitis, as the body typically responds to infection with an increased heart rate due to stress and inflammation. Thus, nausea and vomiting stand out as the correct symptom linked to peritonitis.