Patients with rheumatic fever use aspirin primarily for its anti-inflammatory effects to reduce the inflammatory response. Aspirin also has analgesic properties that can be used to treat symptoms like joint pain associated with rheumatic fever. However, it is crucial to monitor patients taking aspirin for any gastrointestinal reactions, such as stomach pain or black stools. During the use of aspirin, it's important to be vigilant about these gastrointestinal symptoms. Additionally, medications that protect the stomach, such as pantoprazole which reduces stomach acid, can be used to prevent the side effects of aspirin. (Use medication under the guidance of a doctor.)