View source for HIV diarrhea

==Background==
*Chronic [[diarrhea]] (over 28 days); can be presenting symptom of AIDS
*Less common after introduction of HAART
*Acute diarrhea common with normal and low CD4

{{HIV CD4 Chart}}

==Clinical Features==
*Ascertain whether small bowel vs large bowel diarrhea
**Small Bowel
***[[Diarrhea]] watery and copious
***May have weight loss
***Bloating, gas, cramping
***[[Vitamin B12 deficiency]] if terminal illeum involved
**Large Bowel
***Frequent small volume, possibly painful stools
***[[lower GI bleeding|Hematochezia]] - Consider opportunistic pathogens, also consider classic hemorrhagic bacteria ([[E. coli]] O157, [[campylobacter]], [[Shigella]], [[Salmonella]], Yersinia)
*Weight loss is concerning for infiltrative disease, opportunistic infection
*Receptive anal sex - consider local [[HSV]], [[Gonorrhea]], [[chlamydia]], [[entamoeba]]

==Differential Diagnosis==
===CD4 200-500===
*Consider routine pathogens causing [[Diarrhea]] 
**Viruses ([[Norovirus]], [[Rotavirus]], [[Adenovirus]], Astrovirus, etc.)
**Bacteria ([[Salmonella]], [[Campylobacter]], [[Shigella]], Enterotoxigenic [[E. coli]], [[C. diff]], etc.)
**Protozoa ([[Cryptosporidium]], [[Giardia]], [[Cyclospora]], [[Entamoeba]], etc.)
*Side effect of nelfinavir and ritonavir
*[[Kaposi sarcoma]]
*[[Cryptosporidium]] parvum (brief course of illness) - severe watery diarrhea
*[[C. diff]] if antibiotic exposed

===CD4<200===
*[[Microsporidium]]
*[[Cryptosporidium]]
*[[Histoplasma]]
*[[Lymphoma]]
*Enteroaggregative [[Escherichia coli]] (EAEC) (can also affect immunocompetent children)
*HIV can directly infiltrate bowel wall leading to diarrhea

===CD4 <100===
*[[Cryptosporidium]] parvum (chronic course of illness)
*[[M. tuberculosis]] (disseminated disease increasingly likely <100)
*[[Cryptococcus]]
*Isospora

===CD4 <50===
*[[Mycobacterium avium]] complex (MAC) - infiltration of bowel associated with malabsorption 
*[[CMV]]

{{HIV associated conditions}}

==Evaluation==
*Many workups will be non diagnostic
*Start with stool WBCs, cultures, Ova and Parasites x3, C. Dif toxin
*Acid fast smear to assess for Cryptosporidium, Isospora, and Cyclospora
*CD4<100 - Microsporidium more likely, test with Trichrome staining
*Blood cultures with fungal/acid fast if disseminated disease a concern
*Endoscopy
**Indicated if workup is negative and severely immunocompromised 
**Small bowel biopsy to look for MAC, lymphoma, or Microsporidiosis
**Guaiac positive stools and weight loss: consider Kaposi Sarcoma of bowel, diagnosis with colonoscopy
*Imaging
**Generally not helpful, but could be indicated if severe tenderness, peritonitis, concern for biliary pathology, obstructing lesions.

==Management==
*[[electrolyte repletion|Electrolyte]] and [[volume repletion]]
*Early consultation of HIV service
*Nutrition replacement in chronic small bowel disease
*HAART
*Generally, avoid starting antibiotics unless have specific target
*Antimotility agents 
**[[Loperamide]]
**crofelemer (blocks chloride secretion and approved for HIV diarrhea) 125mg po bid

==Disposition==
*If near normal CD4 and symptoms consistent with small bowel disease (copious, watery), may be managed as outpatient if no other admission indication
*Severe dehydration, electrolyte abnormalities, malnutrition, fever, and hemorrhagic diarrhea all may require admission or at minimum very close HIV follow up

==See Also==
*[[HIV - AIDS (Main)]]
*[[Diarrhea]]

==References==
<references/>
*UpToDate: "Evaluation of the HIV-infected patient with diarrhea"
*https://www.aids.gov/hiv-aids-basics/staying-healthy-with-hiv-aids/potential-related-health-problems/opportunistic-infections/

[[Category:GI]]
[[Category:ID]]
[[Category:Symptoms]]