tomatoes - Tomatoes and IBS: What's the Link?

Behind potatoes, tomatoes are the most consumed vegetable. Most of it is consumed in sauces, pasta, pizza, stews, and even fresh salads. Many people experience symptoms after consuming tomatoes. Sometimes these symptoms may not appear until days after eating tomatoes, but still, they do appear, making you feel uncomfortable. Sometimes foods you love may make you sick because they contain tomatoes. When suffering from IBS, it is important to be careful about which foods you consume, and tomatoes are among the foods you should be careful about.


What is IBS?

Irritable Bowel Syndrome (IBS) is a problem that affects about 20% of the world’s population and is observed more in women{1}. IBS can be defined as abdominal discomfort that occurs in association with altered bowel habits over a period of at least three months. It can be challenging to diagnose IBS because there aren’t any specific tests to prove that it’s what you’re suffering from. Also, the symptoms of IBS are similar to those of food intolerances as they dwell in the gastrointestinal tract. Most of the time, IBS is used as a blanket diagnosis once every other condition has been ruled out.

After your doctor has concluded that you might be suffering from IBS, treatment gets challenging, and in many cases, you’ll be advised to go on a low-FODMAP diet as it often causes gut symptoms. To live with IBS but avoid the symptoms can be difficult, and you’ll need to figure out each food individually to see how it can affect your gut and whether you may need to cut it off or not.


Are tomatoes bad for IBS?

Tomatoes are an ingredient in a range of stews and main meals, and it can be hard to pinpoint them as the culprit. IBS symptoms include diarrhoea, abdominal pain, constipation, and bloating. These same symptoms are ones you’ll get after consuming tomatoes if you have a tomato intolerance. Tomatoes are very healthy as they contain minerals, vitamins, phytochemicals, and antioxidants. Besides how healthy they are, they seem to trigger certain symptoms in some individuals. If you experience these symptoms, you need to take a food Intolerance Test which will help you determine whether you have a tomato intolerance or whether it’s just triggering your IBS.

Most people can tolerate small quantities of tomatoes in their system, but large quantities of the same might trigger diarrhoea and stomach bloating. Some people get intolerance symptoms depending on the types of tomatoes they consume, whether raw, cooked, or processed. The reason why tomatoes can lead to IBS symptoms include:


Histamine intolerance

Your body releases histamines in response to something that you’re allergic to. For histamine intolerance to occur, it’s because the histamine levels are too high, and the body is unable to break them down{2}. Tomatoes contain lots of histamines, which often trigger allergic reactions in those sensitive to them. Histamines can also trigger food intolerances, leading to gastrointestinal symptoms like diarrhoea, bloating and abdominal pain. In cases of allergies, one will suffer from symptoms like sneezing, shortness of breath and tongue swelling. When you consume tomatoes, it raises the levels of histamines in your body, and if your body isn’t able to process it, it can trigger an allergic reaction which in some people can result in symptoms like IBS.

A women holding her head.

A women holding her head.

Various foods contain histamines in varying quantities. If your body is finding it difficult to process histamines, eating foods like tomatoes will lead to symptoms like:

  • Diarrhoea
  • Vomiting
  • Runny nose, itchy throat, and watery eyes
  • Headaches
  • Hives
  • Dermatitis

Tomatoes have high amounts of histamines and hence can cause these symptoms in those suffering from tomato intolerance.


High acid levels

Tomatoes are high in malic and citric acid, and when you’re sensitive to these acids, it can lead to acid reflux. Most times, acid reflux presents itself with other symptoms like bloating, abdominal pain, and diarrhoea in some cases due to gut irritation. Heartburn is a common symptom of gastroesophageal reflux disease (GERD), but not everyone experiences it. To experience GERD, you must also experience some of the symptoms like:

  • Coughing
  • Stomach pain
  • Bad breath
  • Nausea
  • Vomiting

Your diet plays a huge role in GERD symptoms. Foods like mint, chocolate, fatty foods, alcohol, caffeine, spicy foods, and acidic foods can lead to some of the above symptoms. Tomatoes and their products are often considered acidic, resulting in a reflux flare-up in many people.


Nightshade intolerance

Nightshades have recently gotten attention due to their association with autoimmune conditions, and tomatoes fall in their category. These claims are because of substances present in nightshades, such as alkaloids. Tomatoes naturally produce an alkaloid called Solanine which functions as an insect repellent. Humans consuming this alkaloid in high amounts can sometimes have gut-related symptoms. Most people who experience these symptoms feel better after they avoid all nightshades. To find out whether you have an intolerance to nightshades, you may need to take a home-lab Intolerance Test.


High FODMAP food

FODMAPs are fermentable oligo, di-, mono-saccharides and polyols. FODMAPs are carbohydrates that are resistant to digestion and can sometimes end up causing IBS symptoms. When you look at the level of tomatoes in all this, they are seen to be low FODMAP, meaning that one can consume them without getting IBS symptoms. However, there are certain preparations of tomatoes that increase the FODMAP value of tomatoes, like tomato ketchup. Different countries produce ketchup in varying ways. For example, Australian ketchup is low in FODMAP, but US ketchup isn’t. So, there are different ways you can consume tomatoes, making them high in FODMAP. Other sources of tomatoes high in FODMAPs are pizza sauce, marinara, and canned soups.


Food poisoning

Sometimes getting IBS symptoms from eating tomatoes could be because of contaminants. Sometimes unwashed tomatoes contain bacteria like salmonella, E. coli, or listeria. However, symptoms of food poisoning are temporary and best managed by staying hydrated and resting. To avoid food poisoning from tomatoes, you need to wash them thoroughly before consuming them and use clean utensils and surfaces when preparing them.


Testing for tomato sensitivity for IBS

TMATMI Intol - Tomatoes and IBS: What's the Link?

Our Intolerance 80 Food Test.

Do you suspect that your tomato intolerance may be causing IBS symptoms? Then you should talk with your doctor and get their thoughts on this. If they tell you that it could be an intolerance or sensitivity to tomatoes, you need to prove this idea. There are many ways tomatoes could be triggering IBS. It could be because you’re consuming tomatoes with high FODMAP, or you’re intolerant to histamines in tomatoes. Either way, you’ll need an Intolerance Test to help you figure out whether it’s only tomatoes causing you these symptoms or if there are other foods you need to eliminate from your diet.

This home-lab test will check your blood against various common intolerances and give you feedback on which foods you need to avoid. By following the correct elimination diet, you will not experience any more IBS symptoms.


Tomato avoidance tips

If you find out that it’s tomatoes that you have an intolerance towards, these tips will help you successfully avoid IBS symptoms.

  • Don’t eat tomatoes from restaurants, or from those who don’t know your allergies and intolerances.
  • Be careful when ordering beef dishes since tomato products are often used to heighten flavour in sauces and gravies.
  • In place of salsa, mash up an avocado with about of salt and use it as a dip for your chips.
  • Be careful when eating anything that contains red sauce and you didn’t personally prepare.


Tomato alternatives

If you’re sensitive to tomatoes, you could decide to prepare all your meals from home for the safety of your stomach. Here are some amazing swaps for your favourite soups, pasta, and salad dishes.

  • Beets add sweetness to salads and pasta sauces.
  • Carrots are great for soups.
  • Grapes are a great swap for cherry tomatoes in your salads.
  • Gooseberries are a good swap for tomatillos in salsa verdes.


Final thoughts on tomatoes and IBS

There is quite a link between tomatoes and IBS. It’s quite unfortunate if your sensitivity to tomatoes could be the reason you’re experiencing IBS symptoms every time you consume these juicy vegetables. If you think that perhaps you could be sensitive to tomatoes, it is important to be sure by taking an Intolerance Test. This test will help you realise other foods that you could be sensitive to and avoid in your diet. Tomatoes are a rich source of vitamin C, E and fibre. Since they’re also low-FODMAP, with the help of your doctor, you can find a way to increase your tolerance to these vegetables so you can enjoy them in your meals.



  1. Rao, S. S., Yu, S., & Fedewa, A. (2015). Systematic review: dietary fibre and FODMAP-restricted diet in the management of constipation and irritable bowel syndrome. Alimentary pharmacology & therapeutics, 41(12), 1256–1270.
  2. Sánchez-Pérez, S., Comas-Basté, O., Rabell-González, J., Veciana-Nogués, M. T., Latorre-Moratalla, M. L., & Vidal-Carou, M. C. (2018). Biogenic Amines in Plant-Origin Foods: Are They Frequently Underestimated in Low-Histamine Diets?. Foods (Basel, Switzerland), 7(12), 205.