Pineapples do not cause diarrhea in healthy adults unless there is an underlying condition. The most common causes of diarrhea from pineapple are food poisoning, a food allergy or food intolerances. If you develop diarrhea from eating pineapple in a single occurrence, the cause of the diarrhea is most likely related to food poisoning. Diarrhea that forms every time you eat pineapple may be caused by an allergic reaction. Your health care provider can provide you with an accurate clinical diagnosis.
Food Poisoning
Food poisoning is a common cause of diarrhea after eating pineapple if the pineapple is contaminated with an infectious organism. The pineapple may be infected because of improper food handling, contamination during the growth and production process or if the fruit was left out at air temperature for too long. Common infectious organisms that could contaminate pineapple include bacteria, viruses, toxins and parasites. Most symptoms will develop within four to 36 hours after you ingest the contaminated pineapple. Symptoms may include excessive diarrhea, vomiting, stomach pain, cramping and a low-grade fever.
Food Allergy
Pineapple is a common food allergy that could cause diarrhea along with other symptoms. If you have an allergy to pineapple, your immune system doesn't recognize the proteins in the fruit as safe. Instead of allowing the pineapple to be digested and used as energy, the body attacks the fruit, causing a chemical chain-reaction. The chemicals cause inflammation in soft tissues throughout the body, such as in the intestines, skin, lungs and sinuses. If you're diagnosed with a pineapple allergy, you will need to avoid consuming pineapple.
Food Intolerances
You can have food intolerance to any food, but diarrhea from eating pineapple may be caused by consuming an ingredient with the pineapple. For example, if you eat pineapple with dairy products, you may be lactose intolerant -- the inability to digest the sugar found in milk. Canned pineapple may contain MSG, a chemical flavor enhancer that has caused headaches, diarrhea, nausea and vomiting in some people.
Consideration
Certain digestive conditions, such as Crohn's disease or irritable bowel syndrome, may cause diarrhea after eating pineapple. Symptoms related to these digestive conditions may be triggered by eating certain foods. Not everyone with these conditions will react to the same foods the same way. If you notice that other foods also cause diarrhea, keep a food log and share it with your doctor.
