A common problem

HIV compromises the immune system and may result in opportunistic infections that cause many symptoms. It’s possible to also experience a variety of symptoms when the virus is transmitted. Some of these symptoms, like diarrhea, may even occur because of treatment.

Diarrhea is one of the most common complications of HIV. It can be severe or mild, causing occasional loose stools. It can also be ongoing (chronic). For those living with HIV, identifying the cause of diarrhea can help determine the right treatments for long-term management and better quality of life.

Diarrhea in HIV has many possible causes. It can be an early symptom of HIV, also known as acute HIV infection. According to the Mayo Clinic, HIV produces flu-like symptoms, including diarrhea, within two months of transmission. They may persist for a few weeks. Other symptoms of acute HIV infection include:

Although these symptoms are like those of seasonal flu, the difference is that a person may still experience them even after taking over-the-counter flu medications.

Untreated diarrhea is especially dangerous. It can lead to dehydration or other life-threatening complications.

Initial transmission of the virus isn’t the only cause of diarrhea with HIV. It’s also a common side effect of HIV medications. Along with diarrhea, these medications can cause other side effects like nausea or abdominal pain.

Antiretroviral medications carry a risk of diarrhea, but some classes of antiretrovirals are more likely to cause diarrhea.

The class with the greatest chance of causing diarrhea is the protease inhibitor. Diarrhea is more often associated with older protease inhibitors, like lopinavir/ritonavir (Kaletra) and fosamprenavir (Lexiva), than newer ones, like darunavir (Prezista) and atazanavir (Reyataz).

Anyone taking an antiretroviral who experiences lasting diarrhea should contact their healthcare provider.

Gastrointestinal (GI) problems are common in people with HIV. Diarrhea is the most common GI symptom, according to the University of California, San Francisco (UCSF) Medical Center. HIV-related GI issues that can lead to diarrhea include:

Intestinal infections

Some infections are unique to HIV, like Mycobacterium avium complex (MAC). Others, such as Cryptosporidium, cause limited diarrhea in people without HIV, but may be chronic in people with HIV. In the past, diarrhea from HIV was more likely to be caused by this type of infection. But diarrhea that’s not caused by intestinal infection has become more common.

Bacterial overgrowth

Small bowel bacterial overgrowth is possible in people with HIV. Intestinal problems may make a person with HIV more likely to have an overgrowth of bacteria. This may lead to diarrhea and other digestive issues.

HIV enteropathy

HIV itself may be a pathogen that causes diarrhea. According to the National Center for Biotechnology Information (NCBI), a person with HIV who has diarrhea for more than a month is diagnosed with HIV enteropathy when no other cause is found.

If diarrhea remains a persistent problem while taking antiretroviral drugs, a healthcare provider may prescribe a different type of medication. Don’t stop taking HIV medication unless directed by a healthcare provider. Forgo HIV medication, and the virus may start to replicate faster in the body. Faster replication can lead to mutated copies of the virus, which can lead to medication resistance.

Scientists have worked to create medications to ease diarrhea. Crofelemer (formerly Fulyzaq, but now known by the brand name Mytesi) is an antidiarrheal prescription medication for treating noninfectious diarrhea. In 2012, the U.S. Food and Drug Administration (FDA) approved crofelemer to treat diarrhea caused by anti-HIV medications.

Diarrhea may also be treated with home remedies and lifestyle changes such as:

  • drinking more clear liquids
  • avoiding caffeine
  • refraining from consuming milk products
  • eating 20 grams or more of soluble fiber per day
  • avoiding greasy, spicy foods

If there is an underlying infection causing diarrhea, a healthcare provider will work to treat it. Don’t start taking any medication to stop diarrhea without first talking to a healthcare provider.

Addressing HIV-related diarrhea can improve quality of life and comfort. But it’s also important to remember that chronic diarrhea can be dangerous and should be treated as soon as possible. Bloody diarrhea, or diarrhea with a fever, warrants an immediate call to a healthcare provider.

The duration of diarrhea in a person with HIV depends on its cause. That person might only experience diarrhea as part of an acute infection syndrome. And they might notice fewer episodes after a few weeks.

Diarrhea may clear up after switching to medications that often don’t cause this side effect. Making certain lifestyle changes or taking medications prescribed to treat diarrhea may provide immediate relief.

Another problem that may affect duration of diarrhea is malnutrition. People with chronic HIV who are malnourished may experience worsened diarrhea. This issue is more common in developing nations where malnutrition is a problem for people with and without HIV. One study estimated that almost 100 percent of all people with HIV in developing regions have chronic diarrhea. A healthcare provider can determine whether malnutrition is an issue and suggest dietary changes to correct it.