Conclusion
It is of paramount importance for clinicians to consider the possibility of GS when adult-onset patients present with thymoma, hypogammaglobulinemia, and recurrent infection. Chronic diarrhea was present in almost up to 50% of GS patients. Additionally, CMV infection is a common opportunistic pathogen and the main cause of diarrhea. The endoscopic manifestations of patients diagnosed with GS and CMV gastroenteritis are also non-specific, mainly characterized by ulcers, inflammation and edema of intestinal mucosa. Therefore, clinical confirmation depends on biopsy results and further immunohistochemical methods. The recognized regime suggests that ganciclovir can be used as the initial therapy, and can be switched to Foscarnet, or combined with both for ganciclovir resistance or symptom recurrence. Finally, it is necessary for GS patients to undertake periodic human immunoglobulin replacement therapy and monitor their immune status,so as to prevent and timely identify opportunistic infection.