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Gastrointestinal Manifestations of HIV Disease

Gastrointestinal and hepatobiliary disorders are among the most frequent complaints in patients with HIV disease. Effective antiretroviral therapy and chemoprophylaxis (PCP, MAC, and CMV) has significantly reduced the occurrence of gastrointestinal opportunistic infections.

Diarrhea

Diarrhea is the most common GI symptom in patients with HIV, affecting 0.9 to 14% of outpatients. Protozoal, viral, and bacterial organisms may cause diarrhea in patients with AIDS. MAC and CMV infections are observed in patients with CD4 cell count <100/mm3. Pathogen-negative diarrhea is the cause of the most cases of diarrhea in this patient group.

Causes of Diarrhea in HIV-Infected Patients and Patients with Advanced HIV Disease

Protozoal/Helminth Infections

Cryptosporidium

Microsporidium

Isospora belli

Leishmania donovani

Giardia

Cyclospora

Entamoeba histolytica

Strongyloides stercoralis

Bacterial Infections

Mycobacterium avium complex

Salmonella

Shigella

Campylobacter sp.

Clostridium difficile

Small-bowel overgrowth

Vibrio parahaemolyticus

Viral Infections

Cytomegalovirus

Herpes simplex

Adenovirus

Picornavirus

HIV

Fungal Infections

Candida albicans

Histoplasma capsulatum

Neoplasms

Lymphoma

Kaposi's sarcoma

Idiopathic

"AIDS enteropathy"

Medications are a common cause of diarrhea in patients with "early" HIV disease, especially protease inhibitors, such as nelfinavir and saquinavir. The diarrhea is often self-limited, lasting for 2 to 4 weeks from initiation of medication.

Small Bowel Overgrowth. Small bowel bacterial overgrowth may cause diarrhea and malabsorption of fat, vitamin B12, and carbohydrates. The prevalence of small bowel bacterial overgrowth with HIV-associated diarrhea is 38%.

AIDS enteropathy. HIV itself may be an indirect diarrheal pathogen. AIDS enteropathy causes diarrhea in HIV-infected patients who lack an identifiable pathogen.

Evaluation of Diarrhea

A careful history should exclude medications, lactose or food/fatty food intolerance, inadvertent use of cathartics (eg, megadoses of vitamin C, lactose-containing medications, sorbitol-containing foods), and symptoms suggestive of a systemic infection or neoplasm.

Cramps, bloating, and nausea suggest gastric or small-bowel involvement secondary to infection with Cryptosporidium, Microsporidium, Isospora belli, or Giardia. Hematochezia and tenesmus imply large-bowel inflammation resulting from CMV, Shigella, Campylobacter, or C. difficile infections. Tenesmus can occur as a result of herpes, Shigella, or Campylobacter infections.

Multiple sexual contacts or receptive anal intercourse increases the possibility of sexually transmitted diarrheal pathogens.

Laboratory evaluation should include stool culture for enteric bacteria, a specimen for Clostridium difficile toxin (in the setting of antibiotic use), and at least three stool specimens for ova and parasite examination (including acid-fast bacilli and trichrome stain). Three or more stool specimens should be tested. If a diagnosis is not reached following careful stool analysis, sigmoidoscopy is appropriate to identify CMV infection.

Management of diarrhea in HIV disease

 

Chronic administration of alternating antibiotics may be necessary for recurrent Salmonella, Shigella, Campylobacter, or Isospora infections. An empiric trial of oral antibiotics or antiparasite therapy for the possibility of small bowel overgrowth, undetected Campylobacter, Isospora enteritis, or undetected protozoa can be considered. Sulfonamides, ciprofloxacin, tetracyclines, or metronidazole may be effective.