II. Epidemiology

  1. Diarrhea is most common intestinal HIV manifestation
  2. Affects 50-90% of HIV patients

III. Signs

  1. Often voluminous Secretory Diarrhea

IV. Causes: Infectious (Pathogen identified in 85% of AIDS patient)

  1. CD4 Count <200/mm3
    1. Cryptosporidium
    2. Cyclospora
    3. Isospora belli (Cyclospora belli)
    4. Microsporidia
  2. CD4 <50/mm3
    1. Mycobacterium Avium Complex (MAC)
      1. May be associated with Hepatosplenomegaly and Lymphadenopathy
    2. Cytomegalovirus (CMV) Infection
      1. Fever accompanies Diarrhea
  3. Bacterial Inflammatory Diarrhea Causes (fever, bloody Diarrhea, esp. Men who have Sex with Men)
    1. Salmonella
    2. Campylobacter jejuni
    3. Shigella
  4. Other Bacterial causes of Diarrhea in HIV
    1. Clostridium difficile
    2. Small intestinal Bacterial overgrowth (SIBO)
      1. Presents with Diarrhea, weight loss, abdominal cramping, excessive Flatulence
      2. Lactulose breath test positive
    3. Mycobacterium tuberculosis
      1. Chronic Diarrhea alternating with Constipation
      2. May be associated with Hepatosplenomegaly and Lymphadenopathy
  5. Other viral causes of Diarrhea in HIV
    1. Herpes Simplex Virus (HSV)
      1. Associated with painful rectal ulcers and erosions
      2. May cause colitis
    2. Typical viral Diarrhea causes
      1. Adenovirus
      2. Rotavirus
      3. Norwalk Virus
  6. Other fungal causes of Diarrhea in HIV
    1. Histoplasma capsulatum
    2. Coccidiodomycosis
      1. Coccidioides immitis may cause peritonitis
  7. Other Parasitic Causes of Diarrhea in HIV
    1. Entamoeba histolytica (Amebiasis)
    2. Leishmania donovani (Leishmaniasis)
    3. Blastocystis hominis

V. Causes: Pathogen negative

  1. Gastrointestinal Cancer
    1. Non-Hodgkin Lymphoma
    2. Kaposi Sarcoma
    3. Anal Squamous Cell Carcinoma
  2. Fat malabsorption (related to pancreatic exocrine insufficiency)
    1. Infectious Pancreatitis (e.g. CMV, MAC)
    2. Drug-Induced Pancreatitis (e.g. Didanosine, Pentamidine)
  3. Sexually Transmitted Disease with secondary Proctitis or anorectal ulcers
  4. Protease Inhibitor related adverse effects
  5. HIV-induced Diarrhea (HIV-Induced Enteropathy or AIDS Enteropathy)
    1. Diarrhea can be chronic (>1 month) and cause malabsorption and severe wasting
    2. More common when CD4 Count <200/mm3
    3. Considered a diagnosis of exclusion
    4. Diagnostic Findings
      1. Small Bowel biopsy with low grade mucosal atrophy
      2. Small Bowel lactase decreased or absent
    5. Unclear etiology
      1. Possibly due to focal mucosal immune defects
      2. Secondary to CD4 Cell Count depletion
      3. Leads to Bacterial overgrowth and mucosal inflammation

VI. Diagnosis

  1. Examine multiple stools first
  2. Stool exam not diagnostic
    1. Upper and lower endoscopy with biopsies and cultures

VII. References

  1. Baloor (2018) Exam Preparatory Manual for Undergraduates Medicine, Jaypee Brothers, India, p. 236-7
  2. Dikman (2015) Dig Dis Sci 60(8):2236-45 +PMID: 25772777 [PubMed]
  3. Feasey (2011) Aliment Pharmacol Ther 34(6):587-603 +PMID: 21777262 [PubMed]

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