think you might have a food intolerance? here’s now to find out.

by team nuut

eating healthily but feel bloated, nauseous, crampy, and, ahem, constipated? you may have a food allergy, intolerance, or ibs.   While the three conditions are often confused for one another and share some common symptoms, they are inherently different and should be treated accordingly.


here, we investigate exactly what each condition is, the symptoms you might be experiencing, and most importantly what to do about it.

what is a food allergy?

a food allergy is an immune system response triggered when the body mistakes an ingredient in food, most often a protein, as harmful and creates antibodies to fight it. these proteins can include shellfish, nuts, fish, eggs, peanuts, and milk.


what is food intolerance?

food intolerance is a digestive system response rather than an immune system response. it occurs when something in food irritates the digestive system or when a person is unable to properly digest or break down the food. intolerance to lactose, found in dairy products, is common as is some natural chemicals found in foods. these include -


  • amines found in pineapples, bananas, vegetables, red wine, chocolate, citrus fruits, and mature cheese
  • salicylates found in some herbs, spices, fruit and vegetables
  • glutamate found in tomatoes, soy sauce, mushrooms and some cheeses.


what is ibs?

ibs stands for irritable bowel syndrome and is a common gastrointestinal disorder that affects bowel function.  its underlying cause is various environmental factors such as infection, emotional stress, changes of routine, food intolerance, diet and hormonal factors.


how do their symptoms differ?

food allergies cause an immune reaction in the body, leading to the development of antibodies which cause sudden symptoms including –


  • hives
  • swelling of the mouth, lips and tongue
  • vomiting
  • diarrhoea
  • breathing difficulties
  • potentially life-threatening anaphylaxis.

ibs symptoms vary in intensity and duration from person to person, but it doesn’t cause lasting damage or contribute to serious bowel conditions like cancer or colitis. most noticeable symptoms include -


  • cramps
  • abdominal pain
  • bloating and gas
  • constipation and/or diarrhoea.


because food intolerance doesn’t involve the immune system, symptoms tend to appear hours or days later and varies between individuals. whilst symptoms are generally not life threatening, they can be super irritating and impact significantly on daily life. symptoms can include –

  • bloating and/or gas
  • nausea
  • stomach cramps
  • constipation
  • diarrhoea


what causes ibs and food intolerance?

ibs and food intolerances can be caused by enzyme deficiencies and carbohydrate malabsorption, that can trigger lactose, fructose, or gluten intolerance. others can relate to chemical compounds found in some foods like flavour enhancers, sweeteners, sulphites, sodium glutamate (msg), preservatives, salicylates, amines, and colourants.


some people are intolerant to various sugars found in fodmap foods. fodmap stands for fermentable oligosaccharides, disaccharides, monosaccharides and polyols. these are the chemical names of sugars that are poorly absorbed in the small intestine. this can include some varieties of fruit and vegetables, breads and cereals, nuts and legumes and confectionary.

what are the most common fodmap triggers?

common trigger foods are termed ‘fodmap’ foods because they contain specific sugars that can be difficult to digest, including fructans, gos (galacto-oligsaccharides), disaccharides (lactose) and fructose. these include -

  • fruits including apples, cherries, pears and peaches
  • vegetables such as artichokes, asparagus, peas, onions and garlic
  • beans, lentils and chickpeas
  • dairy-based milk, yogurt and ice cream
  • processed and marinated meats
  • wheat, barley, and rye-based bread-based products such as cereal, bread and crackers

yikes i have one of the three. what now?

the first step in addressing a food allergy, intolerance or ibs, is to engage an accredited practicing dietitian for professional advice. more than often they will recommend keeping a food diary for at least two weeks so they can consider what foods may be triggering symptoms.


a temporary elimination diet is often implemented next, followed by the gradual re-introduction of foods to attempt to pinpoint the offending chemical or trigger food.

unlike a food allergy where the trigger foods are completely avoided, foods that cause an intolerance can still be eaten in moderation. if necessary, dietitians will recommend substituting foods to counteract any elimination requirements to help maintain adequate nutrition to support good health, growth and overall daily wellness.