Coffee and IBS: Here's what you need to know

If you’re like me, you need a strong cup of coffee each morning before you can function properly.  That hot cup of happiness can take you from “god help anyone who tries to talk to me right now” to “I’ve had a taste of heaven and am ready to smash out the day ahead.” For those with IBS, however, that morning cup of coffee may not go down so smoothly.

You may have sadly noticed your symptoms flare up after drinking coffee. You aren’t alone – coffee is frequently reported as a trigger food by IBS sufferers.  Coffee seems to most commonly trigger symptoms of indigestion/reflux, stomach pain, and diarrhoea in those with IBS.

Why can coffee worsen IBS symptoms?

The main reason coffee commonly worsens IBS symptoms is the high caffeine content.  Caffeine is the substance in coffee that helps to boost energy levels and alertness.  While this caffeine fix from coffee often helps sustain sanity during a busy workday, it isn’t often doesn’t help with symptom management.  

Caffeine increases stomach acid production (causing pain and indigestion) and stimulates motor activity levels in the colon/gut (causing diarrhoea). Those with diarrhoea-predominant IBS are usually more affected by coffee than those with constipation-predominant IBS.

Do other caffeinated products trigger IBS symptoms?

Yes, any food rich in caffeine can worsen IBS symptoms in sensitive individuals.  Coffee is usually worse for symptoms than other caffeinated products as it is generally much higher in caffeine.  Other caffeinated products to be mindful of include tea, energy drinks, dark chocolate, soft drinks (especially cola), and pre-workout supplements.

Uhhh… please don't tell me this means no coffee on a low FODMAP diet!?

Here comes the good news, most people with IBS should tolerate coffee in moderate amounts. Those with IBS who are sensitive to caffeine should limit coffee and tea to no more than 3 cups per day. This means you should be fine with your essential morning cup of coffee to kick start the day (phew!).  

Try having a half-strength or decaf coffee if you find you are particularly sensitive and don’t manage to tolerate a whole cup.  You can also swap the coffee for tea, which has lower caffeine content.  

Green tea is also a great lower-caffeine alternative to coffee and has some awesome health benefits because it contains antioxidants.

Content of common caffeinated products

Below is a list of the caffeine content in common products, as listed by Australian Food Standards Australia and New Zealand (FSANZ).  Try limiting caffeine intake to no more than 150mg-200mg per day, (approximately 2-3 cups of coffee/tea).

1. Instant coffee = 60-80mg per teaspoon (approximately 1 cup)
2. Filtered coffee (from coffee machine) = 60-120mg per 250ml cup
3. Tea = 10-50mg per 250ml cup (strength depends on brewing time)
4. Energy drinks = 80mg per 250ml can
5. Coca Cola = 48.75mg per 375ml can
6. Dark chocolate = 21mg per 50g (approximately 2 rows)

Need help with the low FODMAP diet? Our FREE dietitian developed program will guide you through it, step-by-step. Includes a low FODMAP food guide. Sign up now.

If you are experiencing gut symptoms and have not been recommended a low FODMAP diet by a health professional, get started with the manage your gut symptoms program.

Reviewed by the healthylife Advisory Board March 2022