Can Caffeine make my IBS Symptoms worse?

Introduction

Are you someone who enjoys that morning cuppa or loves to indulge in your favourite chocolate bar but worry about it making your IBS symptoms worse?

In this blog we will look a little deeper into:

What caffeine is and where do we find it?
Common sources of caffeine and their content
UK recommended intake
A little bit about what the research says
Other possible factors alongside caffeine that may trigger symptoms.

What is caffeine and where do we find it?

Caffeine is a natural chemical found in coffee beans, tea leaves, and cocoa plants. It is widely known for its stimulating effects on the central nervous system which make some of us feel more alert, boost wakefulness, and can enhance our cognition and exercise performance (1). For some of us, caffeine can be a great addition to your day, particularly before tackling a challenging task, or taken as a pre-workout boost. For some people, caffeine helps to improve gut movement and can stimulate the need to pass a stool (2). This effect may be helpful for some, but can make symptoms worse for some people with IBS, particularly for those with diarrhoea as a main symptom.

Common sources and their caffeine content (3)

Source	Caffeine Content (mg)
Mug of filter coffee	140
Mug of instant coffee	90
Shot of Espresso	65
Can of Energy drink	170
Mug of black tea	70
Mug of green tea	42
Can of Cola	40
Small bar of chocolate	25-50
Caffeine supplements	200
Guarana	125

Recommended intake

The current UK recommendations for caffeine intake in the general public is up to 400 mg per day, this is roughly 3 cups of coffee. No more than 200mg per day is the recommendation if you are pregnant or breastfeeding. The National Institute for Health and Care Excellence (NICE), encourages people with IBS to drink less caffeine. It is advised to keep caffeine intake down to two mugs of coffee per day (4).

But where does this advice come from? And should you be changing your caffeine intake to improve IBS symptoms?

What does the research say?

Several studies which looked into the relationship between caffeine and IBS found that caffeine can affect IBS symptoms (5,6,7). Women were more affected by caffeine than men (6). Coffee has been considered the 7th most common trigger of IBS symptoms (5). Interestingly though, the effects of tea on the gut were different. People within the studies noticed they experienced hard stools after drinking tea, whereas loose stools, reflux/heartburn, and abdominal pain were noticed following coffee consumption. Just to make things a bit more confusing/complicated, the research out there is limited, and the results are varied. For example, one study even found no link between caffeine and IBS (8)! That said, we understand how hard/challenging it can be to navigate the world of IBS, particularly when there is no advice which is one-size-fits-all.

So how does caffeine actually make our symptoms worse?

Possible factors which may contribute to IBS symptoms

Laxative effect

Caffeinated drinks, such as coffee, can stimulate gut movement in healthy people (2). It stimulates activity in a portion of the large bowel which may make you want to poop. This is due to the laxative effect that caffeine has in some people (2), especially if diarrhoea is a main symptom of their IBS. If you struggle with diarrhoea, it may be worth testing to see if a reduction in caffeine improves your symptoms.

Increased stomach acid and reflux

In-between the stomach and the gullet (also known as the oesophagus) is a ring of muscles called the oesophageal sphincter. This ring of muscles keeps the content of the stomach in the stomach and prevents it from going up into the gullet.

Stomach acid is a watery fluid that is highly acidic and is produced by your stomach’s lining. The function of the stomach acid is to break down food and kill bacteria. Caffeinated drinks such as coffee, may relax this ring of muscles and also increase stomach acid(2). This can increase the likelihood of getting acid reflux or heartburn even if you do not have IBS.

FODMAPs

How do you take your coffee? Do you add milk or cream? Milk is considered a high FODMAP food because it contains a natural sugar called Lactose. Lactose is a disaccharide (the “D” in FODMAP) because it contains two sugar molecules and need an enzyme called Lactase to break if apart.

FODMAPs are a group of fermentable carbohydrates (sugars) that can cause digestive issues in people struggling with IBS. People who are intolerant of Lactose do not produce enough Lactase and the undigested lactose will ferment in the gut causing excessive gas and bloating (2).

If you struggle with excessive bloating and flatulence, it may be worth looking at what else you have with your coffee and experiment with different amounts.

Fat

Have you considered that some of the caffeinated foods and drinks you are having may be high in fat – foods such as chocolate? Cutting down on fatty foods is part of the dietary advice in managing IBS symptoms (4). The reason for this is, when fat is eaten in high amounts, it can slow the movement of food within the bowel causing gas and bloating (2).

Summary

There is no one-size-fits-all in the dietary management of IBS. The key to IBS management is to understand what triggers your symptoms. Caffeine may be a trigger for people with Diarrhoea -predominant IBS and in these cases it may be better to reduce the amount of caffeine. Reducing caffeine intake may also help people who struggle with reflux and heartburn.

On the other hand, due to the laxative effect of caffeine, it may be useful for people who struggle with constipation. Ultimately, there is a lack of high-quality evidence to suggest caffeine is associated with IBS symptoms and understanding individual triggers is the way forward.

If you are unsure of what your IBS triggers are, this IBS Symptom and Trigger tracker may be helpful. A Registered Dietitian may also be able to help you identify your triggers and determine if your symptoms relate to caffeine intake.

I help individuals who struggle with Irritable Bowel Syndrome and Digestive issues manage their symptoms, so they can get back to living a confident life.

Post written by Eleanor Sinclair, Registered Dietitian and reviewed and edited by Christel Lyell.

References

Nehlig, A., Daval, J. L. and Debry, G. (1992) Caffeine and the central nervous system: mechanisms of action, biochemical, metabolic and psychostimulant effects. Brain research. Brain research reviews, 17 (2) May-Aug, pp. 139-170.
Cozma-Petrut, A., Loghin, F., Miere, D. and Dumitrascu, D. L. (2017) Diet in irritable bowel syndrome: What to recommend, not what to forbid to patients! World Journal of Gastroenterology, 23 (21) June, pp. 3771-3783.
Capili, B., Anastasi, J. K. and Chang, M. (2016) Addressing the Role of Food in Irritable Bowel Syndrome Symptom Management. The Journal for Nurse Practitioners, 12 (5) May, pp. 324-329.
NICE (2008) Irritable bowel syndrome in adults: diagnosis and management [CG61]. Available from: <https://www.nice.org.uk/guidance/cg61/chapter/recommendations> [Accessed 16 November 2022].
Simrén, M., Månsson, A., Langkilde, A.M., Svedlund, J., Abrahamsson, H., Bengtsson, U. and Bjornsson, E. S. (2001) Food-related gastrointestinal symptoms in the irritable bowel syndrome. Digestion, 63 (2) pp. 108-115.
Faresjö, A., Johansson, S., Faresjö, T., Roos, S. and Hallert C. (2010) Sex differences in dietary coping with gastrointestinal symptoms. Eur J Gastroenterol Hepatol, 22 (3) March, pp. 327-333.
Hayes, P., Corish, C., O’Mahony, E. and Quigley, E. M. (2014) A dietary survey of patients with irritable bowel syndrome. J Hum Nutr Diet. 27 (2) April, pp. 36-47
Reding, K. W., Cain, K.C., Jarrett, M.E., Eugenio, M.D. and Heitkemper, M. (2013) Relationship between patterns of alcohol consumption and gastrointestinal symptoms among patients with irritable bowel syndrome. Am J Gastroenterol. 108 (2) February, pp. 270-276.
Boekema, P. J., Samsom, M., Berge Henegouwen, G. P. and Smouth, A. J. (1999) Coffee and gastrointestinal function: facts and fiction. A review. Scandinavian Journal of Gastroenterology Supplement, 230 (1), pp. 35-39.