Why Coffee May Make Your IBS Symptoms Better or Worse

When you see a picture of coffee, do you start thinking about the pleasant aroma and bold flavor? Or, does your mind immediately go to you rushing to the bathroom?

People with IBS can have very different relationships with coffee, depending on the effects they experience when they drink it. Coffee is low FODMAP, so it’s not completely off limits on a low FODMAP diet, but it can either make symptoms much better or much worse for those with IBS. Many people think that coffee is ultimately “bad” for IBS so they eliminate it without actually knowing if it can work for them.

About 26-40% of those with IBS claim coffee as a trigger for diarrhea and stomach pain. Why? The caffeine in coffee stimulates the gut to function more quickly, increasing gut motility. For those with IBS-D, this can be problematic because gut motility is already faster than it should be. This is also problematic for those with IBS who are experiencing anxiety or high levels of stress, because that tends to create a more spasmodic effect for the gut, and caffeine may make that worse. Caffeine can also increase heart rate, which may heighten the stress response, and then causing more symptoms.

For those with IBS-C, the stimulating effect of caffeine from coffee can be helpful to get the bowels moving each morning. There is a limit, though, as too much caffeine can still lead to abdominal cramps, even for those with IBS-C.

So, is coffee “good” or “bad” for IBS? Depends on your symptoms, how much you’re drinking, and when you’re drinking it!

How much should you have?

Before deciding whether or not to have or eliminate coffee for good, take it away for a week or two, then reintroduce it in a small portion. Slowly increase your portion to test your tolerance. If coffee doesn’t seem to trigger your symptoms, then you should be safe to incorporate it into your life.

If you do decide to include coffee, keep your caffeine intake to around 400 mg per day, or less. Most people complain of coffee first because it is highest in caffeine, but other caffeine sources can still become problematic in larger amounts.

Sources of caffeine:

  • 8 oz coffee 95-165 mg

  • 8 oz cold brew 100-150 mg

  • 8 oz decaf coffee 2-5 mg

  • 1 oz espresso 47-64 mg

  • 8 oz black tea 25-48 mg

  • 8 oz green tea 25-29 mg

  • 8 oz soda 24-46 mg

  • 50 g dark chocolate 21 mg

  • Energy drinks (varies by brand)

  • Pre-workout supplements (varies by brand)

What about the acidity of coffee?

A lot of people will say that drinking less acidic coffee, like cold brew, is more tolerable. While the caffeine may be the same, the acidity of the coffee can lead to stomach pain and indigestion. These aren’t necessarily IBS symptoms, but can still be frustrating and uncomfortable. Like you would with caffeine, test your tolerance for the acidity in coffee by taking it away for a while, then introducing a small amount of a less acidic coffee, like 6-8 oz cold brew, then increasing your portion and moving to a more acidic coffee, like a traditionally brewed hot coffee.