The evaluation of abdominal pain in patients with HIV can be narrowed due to the high risk of infection that occurs in this population. Additionally, one is more likely to move to abdominal CT earlier on due to the risk of infection invasive infection. The differential diagnosis for chronic abdominal pain in HIV can be categorized as follows:
1. Infection: Luminal infection with CMV (most common cause), Cryptosporidium, H. Pylori, MAC, Salmonella, Histoplasma, HSV. Mesenteric infiltration with TB, toxoplasmosis, or coccidiomycosis. Pancreatitis due to CMV, cryptosporidium. Cholangitis due to usual offenders due to AIDS cholangiopathy.
2. Drug Reaction: NRTI and NNRTI can both cause GI upset. Many antibiotics used as prophylaxis against infection can cause GI upset. Bactrim and Pentamidine can both cause pancreatitis.
3. Malignancy: Lymphoma or Kaposi Sarcoma infiltration.
4. Other: AIDS cholangiopathy. Intussusception. Consider other causes in general population.