Cox’s Conference: Chronic diarrhea in a patient with AIDS

Today’s Cox’s Conference was presented by Dr. Nivi Arora with expert discussant Dr. Emre Turer.  


Dr. Arora presented a 27 year old man with no known past medical or surgical history who presented with 1 year of diarrhea characterized by 6 to 10 bowel movements per day, watery consistency, and occasional blood and mucous. This was also associated with subjective weight loss. His social history was notable for occasional methamphetamine abuse and MSM status. He had no significant family history. He had no allergies and was not taking any medications. His physical exam was notable for a chronically ill appearing, thin man. He was without rash. His digital rectal exam was notable for multiple peri-rectal verroucous warts and a non-painful ulcer. He was found to have HIV/AIDS with a CD4 count of 109 cells/microliter. RPR was positive. Stool cultures were positive for Shigella flexneri. Colonoscopy was notable for multiple violaceous nodules in the colon. Biopsy demonstrated spindle-shaped cells with high vascularity consistent with gastrointestinal Kaposi’s sarcoma, and intra-nuclear inclusions consistent with CMV.


HIV/AIDS complicated by gastrointestinal Kaposi’s sarcoma, CMV colitis, primary syphilis, and Shigella flexneri


-The differential diagnosis for diarrhea in a patient with HIV is quite broad and includes the following:

Infectious: MAC, tuberculosis, cyclospora, microsporidia, isospora, cryptosporidiosis (typically persistent and severe if CD4 < 180 cells/microliter), Histoplasmosis, cryptococcus, giardiasis, spirochetosis, C diff, CMV colitis, HSV, E coli, Campylobacter jejuni, Shigella, Salmonella, Yersinia (a mimicker of terminal ileal IBD), rotavirus, norovirus

Malignant: infiltrative lymphoma or Kaposi’s sarcoma

Auto-immune: inflammatory bowel disease (Crohn’s disease, ulcerative colitis, indeterminate, microscopic colitis)

Medication-induced: particular attention to anti-retroviral therapy, antibiotic-induced diarrhea

Malabsorptive disease: pancreatic insufficiency, celiac disease, small intestinal bacterial overgrowth (SIBO)

-In contrast to most patients, diarrhea in an immunocompromised patient may often be multifactorial, as is the case in this patient. The rules of parsimony in medicine may fail you in the workup of diarrhea in HIV.

-Clues about areas of gastrointestinal involvement:

Small bowel:  stool is typically large volume and watery; association with weight loss and nutrient malabsorption

Large bowel: small volume stool, watery, no weight loss

-unprotected receptive anal intercourse may increase concern for HSV, spriochetosis, gonrorrhea, Chlamydia