Advanced diagnostic tests are used to accurately diagnose patients with undetermined causes of their digestive or systemic symptoms. These tests include specialised endoscopic biopsy procedures, molecular testing, and imaging studies, which will help clinicians identify the exact nature of the infection and the affected areas of the body. A multidisciplinary approach is required to provide a proper diagnosis, an individualised treatment plan, long-term management of the patient's condition, and prevention of life-threatening illness from complications involving the digestive, central nervous, and cardiovascular systems.