Citrus Fruit Like Oranges Can Cause Diarrhea for Some People — Here's Why

Oranges and grapefruits (and all citrus fruit, really) are chock-full of essential vitamins and nutrients — making them a great snack or addition to your diet.

But if you have an underlying GI condition like IBS, Crohn's disease or fructose malabsorption, fruit juices like grapefruit and orange juice could cause digestive upset like diarrhea.

Oranges can also cause diarrhea if they're contaminated or their juice in unpasteurized.

Here, learn the reasons why citrus fruits (including juice) could cause or worsen diarrhea, and how to get relief.

Diarrhea is characterized as having frequent bowel movements that may be loose or watery in nature. It's a pretty common condition — affecting 179 million Americans every year, according to the National Institutes of Health (NIH).

You may experience abdominal cramps or belly pain, and your need to defecate may be immediate. You may also become dehydrated when you have diarrhea, especially if it's accompanied by vomiting.

Usual causes of diarrhea include the following, per Penn Medicine:

• Bacterial or viral infections
• Parasites
• Bowel disorders
• Medication reactions
• Contaminated food or water
• Food sensitivities or allergies

Luckily, most cases of diarrhea are short-lived and only last a few days — also known as acute diarrhea.

But if it lasts longer than four weeks, it's considered chronic diarrhea, and it may be a sign of an underlying health issue, such as a food intolerance, allergy or a condition that affects your digestive system like irritable bowel syndrome (IBS) or celiac disease, per the NIH.

While citrus fruits like oranges, grapefruits, lemons, limes and tangerines are rich in antioxidants, flavonoids and vitamin C (which are nutrients that may protect against heart disease and cancer), these fruits can also cause digestive issues for some people.

Common causes of diarrhea from oranges or other citrus fruits include:

Turns out, citrus fruits can be host to several different foodborne illnesses, including Salmonella and the norovirus, per the University of Connecticut. This is especially true if they are in juice form.

Diarrhea is a common symptom of Salmonella and norovirus infections, along with abdominal pain, fever and vomiting. These symptoms may last as long as five to seven days, according to the Food and Drug Administration.

Though citrus fruits offer many health benefits, you shouldn't eat them if you have an allergy to citrus fruits. Food allergies can cause an array of symptoms, including digestive issues like diarrhea, per the Mayo Clinic.

However, according to a January 2013 study in ‌PLOS One‌, citrus fruit allergies are most often caused by an allergy to pollen and are more likely to cause the type of symptoms you'd expect with hay fever, such as a runny nose, itchy eyes, scratchy throat or sneezing.

Still, abdominal symptoms such as pain, nausea or vomiting are possible. The authors of the ‌PLOS One‌ study note that participants with abdominal pain and diarrhea were more likely to have a systemic food allergy. This is a more serious allergy that increases the risk of anaphylaxis, a life-threatening condition that requires immediate medical attention, per American Family Physician.

Symptoms of anaphylaxis include difficulty breathing, a swollen throat or tongue, skin that feels cold to the couch and feeling faint or confused. If you have any of these symptoms, call 911 or go to the nearest emergency room.

Keep in mind, true citrus allergies are not common. If you suspect an allergy, talk to your doctor; they can provide the right diagnosis and treatment recommendations.

If you are allergic to citrus, you're likely allergic to limes and lemons as well as oranges and grapefruit. Symptoms will include the following, per the National Health Service:

• Itching around the mouth
• Asthma
• Hives
• Stomach pain
• Vomiting or diarrhea

These symptoms may begin within minutes or up to an hour after you drink or eat citrus.

This is different from a citrus fruit intolerance or sensitivity, which could include abdominal pain, nausea, bloating, gas and diarrhea, but symptoms are localized to the digestive system, per the Cleveland Clinic.

If you have a bowel disorder such as IBS, Crohn's disease or fructose malabsorption, drinking citrus juices may be causing your diarrhea.

If you have IBS, it's important to monitor your diet and avoid eating foods that may make your symptoms worse. Citrus fruits, including oranges and grapefruits, are often noted for worsening the symptoms of IBS, per a May 2017 report in the ‌Journal for Nurse Practitioners‌.

Other IBS triggers include caffeine, alcohol, dairy products and fried and fatty foods. Other symptoms include:

• Bloating and gas
• Always feeling like bowel movements are incomplete
• Bowel movements that contain mucus
• Severe or mild cramping or abdominal pain that usually goes away after a bowel movement

Crohn's disease is a more serious digestive condition marked by the following symptoms, which may come and go, per the Mayo Clinic:

• Fever
• Fatigue
• Abdominal pain and cramping
• Blood in the stool
• Mouth sores
• Weight loss
• In severe cases, kidney stones, anemia and inflammation of the skin, eyes and joints

With fructose malabsorption, your body is unable to process the sugar called fructose found in fresh fruits like oranges and grapefruit. Diarrhea is a common symptom, per the National Library of Medicine.

In some cases, orange and grapefruit juices can cause diarrhea if they are unpasteurized.

When juice is pasteurized, it is heated up to kill off bacteria before being sold. Without pasteurization, juice can become infected with harmful bacteria that can make you sick, causing gastrointestinal problems such as diarrhea, per the University of Connecticut.

Fortunately, 98 percent of the juice sold in the United States is pasteurized, per the City of Houston.

In addition to diarrhea, symptoms of infection from unpasteurized juice (with bacteria) include a high fever, headache, vomiting, nausea and stomach cramps. Symptoms develop 12 to 72 hours after consumption, per the City of Houston.

If you have diarrhea that's not from a GI condition or oranges themselves (due to infection or allergy), citrus might actually be able to help you rehydrate after an episode of diarrhea.

Turns out, the nutritional profile of oranges make them a good choice for managing the ill effects of loose, watery stool. Dehydration and electrolyte imbalance are common complications of diarrhea, per the NIH, and citrus fruits are a good source of water and electrolytes that can help replenish you.

Tangerines (or mandarin oranges), in particular, may be your best option, as they are a good source of potassium and sodium, but are also low in fiber — a diet choice recommended for those going through bouts of diarrhea, per the University of Pennsylvania.

Orange juice could also rehydrate you after episodes of diarrhea, as it has about 12 percent of your daily value of potassium, per the USDA.

Orange and grapefruit can cause diarrhea if they contain a foodborne bacteria, if you're allergic to them or if you have an underlying bowel disorder.

Otherwise, citrus fruits like oranges and grapefruit are a great source of vitamin C, potassium and other essential vitamins and minerals, and they can be part of a healthy, balanced diet.