Chronic Diarrhea: 6 Common Causes & How to Stop It

Medical review: Dr. Clarisse Bezerra
Family Doctor
January 2023

Chronic diarrhea can be caused by a number of factors, but the most common causes are viral or bacterial infections, prolonged use of medications or food allergies.

Constant diarrhea can also be a result of changes in the intestines, or a more serious condition, like intestinal cancer, especially if it occurs with symptoms like abdominal pain, nausea or vomiting. 

Treatment of chronic diarrhea depends on what it is causing it. Nonetheless, you should ensure you are maintaining hydration by drinking plenty of fluids and electrolytes. You can also take medication that helps to stop diarrhea, however these should only be used as recommended by your doctor.

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What causes chronic diarrhea?

Chronic diarrhea can occur for the following reasons: 

1. Intestinal infection

Viral or bacterial infections will generally cause sudden, intense diarrhea that is often accompanied by other symptoms like nausea, vomiting, headache, muscular pain, fever, chills, loss of appetite, weight loss and abdominal pain. Infections causes by parasites, on the other hand, will take longer to develop and symptoms appear later and last for longer. 

These types of infections usually occur due to ingestion of contaminated food or water or of raw or uncooked food. Foods that are more frequently contaminated include milk, meat, eggs and greens. 

Learn more about the symptoms of an intestinal infection and what can cause them.

How to stop it:  Treatment for diarrhea caused by viral infections should be aimed at preventing dehydration. Make sure you are drinking plenty of water and electrolytes. More serious cases may require IV hydration. 

Treatment for food poisoning from parasites or bacteria depends on the underlying bug and the intensity of symptoms. However, you can treat this at home by ensuring adequate hydration and avoiding foods with fat, lactose and caffeine. You should see your doctor to start treatment with antibiotics and anti-parasitics if your symptoms are intense. 

Check out some home remedies for an intestinal infection that you can try to relieve mild symptoms naturally.

2. Prolonged use of medications 

Some medications, like antibiotics, cancer medications or antacids with magnesium can cause diarrhea. Diarrhea from antibiotics occurs because this medication eliminates both harmful and good bacteria in the body. By attacking the good bacteria, the intestinal flora becomes affected, impeding with normal digestion. Depending on the medication, diarrhea can be chronic, especially if this is a medication that is taken every day. 

How to stop it: When taking antibiotics, you can prevent or reduce diarrhea by also taking a probiotic. Probiotics contain good bacteria that can support the intestine and maintain flora levels. Magnesium antacids that cause diarrhea can be swapped for other types. Learn more about ways your can stop diarrhea

3. Lactose intolerance

Lactose in a sugar that can be found in milk and dairy products. Some people are intolerant to this sugar because they do not produce sufficient amounts of lactase. Lactase is an enzyme that helps with the breakdown of lactose into simple sugars that can be easily absorbed. People that are lactose intolerant will commonly experience chronic diarrhea when they consume milk and dairy.

Babies may also have diarrhea when they consume lactose because their digestive system is still immature and may also not produce enough lactase to digest milk correctly. Therefore, mothers who are breastfeeding may be advised to reduce their intake of dairy and to avoid introducing dairy products to babies less than 6 months of age. Read more about diarrhea during pregnancy

How to stop it: To prevent gastrointestinal symptoms caused by lactose, you should reduce your intake of milk and dairy products, and opt for alternative or lactose-free options- You can also take lactase enzymes prior to meals to prevent symptoms.

4. Intestinal changes  

Illnesses like Crohn’s disease, ulcerative colitis, celiac disease or irritable bowel syndrome are associated with many flare-ups of chronic diarrhea, nausea and vomiting. Symptoms will especially be felt after eating heavier foods, or foods that trigger worsening.  

How to stop it: Many of these illnesses do not have a cure. Treatment is aimed at relieving associated symptoms with medication and maintaining hydration. If you have been diagnosed with an intestinal condition, you should adhere to a medically-recommended diet and avoid foods like caffeine, raw vegetables, fruit with peels, dairy products, oatmeal, fatty food, fried food, sweet and red meat. 

Learn more about other home remedies for diarrhea that you can try. 

5. Food allergies  

A food allergy is an exaggerated response of the immune system to specific foods like eggs, milk, peanuts, wheat, soy, fish or seafood. It can affect several areas of the body, like the skin, eyes, and nose, and can cause symptoms like vomiting, abdominal pain and diarrhea. It is important to identify foods that trigger a food allergy and avoid them, as reactions can be life.threatening. 

How to stop it: Treatment for a food allergy depends on the severity of symptoms. Mild reactions can be treated with anti-histamines or corticosteroids. Serious reactions that lead to anaphylactic shock are treated with epinephrine injections and supplemental oxygen.

You should avoid the foods that trigger a reaction. To determine which foods you are allergic to, you can complete a food intolerance test. 

6. Intestinal cancer

Generally, intestinal cancer causes chronic bloody diarrhea with abdominal pain, fatigue, anemia and weight loss with no other apparent cause. If these symptoms persist for over a month, you should seek medical attention to start treatment as soon as possible. Read more about the potential signs and symptoms of cancer that you should look out for. 

How to stop it: Treatment for intestinal cancer can involve surgery, chemotherapy, radiation therapy and/or immunotherapy. The treatment approach depends on the location of the cancer, the size of the tumor and if it has metastasized. 

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Edited by Tua Saude editing team in January 2023. Medical review completed by Dr. Clarisse Bezerra - Family Doctor in April 2022.

References

  • ÁLVAREZ María Luisa et al. Nutrición en pediatría . 2ª. Caracas, Venezuela: Cania, 2009. 694-696.
  • MAHAN, L. Kathleen et al. Krause: Alimentos, Nutrição e Dietoterapia. 13.ed. São Paulo: Elsevier Editora, 2013. 352-364.
Show more references
  • SECRETARIA MUNICIPAL DE GESTÃO E CONTROLE. Orientação nutricional para a diarreia. 2019. Available on: <http://www.saude.campinas.sp.gov.br/especialidades/nutricao/Orientacao_nutricional_para_Diarreia_FO1224.pdf>. Access in 03 Dec 2019
  • EDUFBA. Manual Básico para Atendimento Ambulatorial em Nutrição. 2008. Available on: <http://books.scielo.org/id/sqj2s/pdf/villela-9788523208998.pdf>. Access in 03 Dec 2019
  • MORAES, Antônio C.; CASTRO, Fernando M.M. Diarreia aguda. JBM. Vol.102, n.21. 21-28, 2014
Medical review:
Dr. Clarisse Bezerra
Family Doctor
Dr. Bezerra possesses a medical degree and specializes in family medicine. She is licensed to practice under CRM-CE licence #16976.