Can raw oysters cause diarrhea?

Eating raw oysters can put an individual at risk for health issues including diarrhea if not careful. Once an individual experiences diarrhea after eating raw oysters, it might be an indication of a shellfish allergy or food poisoning which initiates the digestive tract to rapidly eliminate the detrimental substance out of the body.

Diarrhea is considered as a normal condition that usually lasts for a few days, but there are some cases in which it persists longer. If diarrhea persists, it can lead to dehydration and might require treatment under the guidance of a doctor.

Overview on shellfish allergy

Shellfish allergy is considered as the most prevalent food allergy among adults. This allergy is a long-lasting condition that has no known cure but can be managed. Shellfish allergy can lead to a severe allergic reaction or anaphylaxis.


The diarrhea due to food poisoning is managed with adequate rest, increased intake of fluids and avoidance of certain foods.

During an allergic reaction to oysters, the immune system does not recognize the proteins present in the seafood and triggers an attack using antibodies and histamine. The presence of histamine in various soft tissues in the body results to the evident swelling and irritation.

Food poisoning after eating oysters

Food poisoning is a condition which develops after ingesting a certain food that contains toxins, viruses, parasites or bacteria. Once an individual consumed raw food including oysters, he/she is at high risk for developing food poisoning. The indications of food poisoning usually develop 2-6 hours after consuming the food but can be delayed until the next day.

What are the effects?

Take note that both conditions generate digestive symptoms such as the following:

  • Vomiting
  • Nausea
  • Abdominal cramping
  • Stomach pain
  • Diarrhea
  • Gas
  • Bloating

When it comes to an allergic reaction to raw oysters, it can be accompanied by other symptoms not related to the digestive tract such as skin rashes, asthma and nasal congestion.

Management of diarrhea

The minor allergy symptoms can be managed with antihistamines. The diarrhea due to food poisoning is managed with adequate rest, increased intake of fluids and avoidance of certain foods. It is recommended to drink juice, water and soup broth but avoid pear or apple juices since they can aggravate the condition.

Once the diarrhea starts to subside, you can add small meals that include bland foods such as eggs, rice, toast and chicken. The individual should avoid highly seasoned foods, fatty foods and dairy products until the diarrhea completely subsides.

If the diarrhea occurs along with hives, facial swelling, mental confusion, shortness of breath and lightheadedness are indications of anaphylaxis. The elevated levels of histamine that is released can cause the body to progress to a state of shock and anxiety.


No comments yet.

Leave a Reply

Please solve captcha * Time limit is exhausted. Please reload CAPTCHA.