HIV infection can be divided into acute phase, asymptomatic phase and AIDS phase. Patients may develop diarrhea mainly in the acute phase, i.e. 1-3 weeks after infection, or in the AIDS phase: 1. Acute phase: 1-3 weeks after a patient is infected with AIDS belongs to the acute phase of AIDS, during which the patient will experience a series of flu-like symptoms, such as diarrhea, nausea, vomiting, dizziness, joint pain, etc.. However, the acute phase is usually not too long, usually lasting about 10 days, and the symptoms will gradually subside on their own; 2. AIDS phase: After the patient has spent the acute phase of AIDS, he/she will enter the asymptomatic phase and then the AIDS phase. The asymptomatic period is longer and may last 10-20 years, while patients in this period have no obvious abnormal symptoms. Therefore, when a patient with AIDS reappears with diarrhea, he or she is mostly in the AIDS phase. Patients in this period may have fever, diarrhea, weight loss, and swollen superficial lymph nodes throughout the body, often combined with various conditional infections such as oral candidiasis, pneumonia, cytomegalovirus infection, herpes virus infection, toxoplasma infection, cryptococcal meningitis and active tuberculosis, as well as tumors such as Kaposi’s sarcoma and lymphoma. Patients in this period have had their immune system destroyed and often present with tumor-induced diarrhea, which may be accompanied by abdominal discomfort and pain, and should be differentiated.