Alcohol and its effects on digestive tract


For many, alcoholic beverages are an obvious part of any celebration such as birthdays, New Year, or Christmas. However, those who struggle with an upset stomach are often advised to evaluate their alcohol consumption, as alcohol and the stomach are not considered an ideal combination. A reduction in its consumption is advocated as a favorable starting point, but the question remains: Is it only the alcohol content that matters, or are there differences between the various alcoholic beverages? This article highlights some of the effects that alcoholic drinks can have on the gastrointestinal tract, particularly for people with irritable bowel syndrome (IBS).

Digestive problems are common with alcohol

Of those who suffer from IBS, over a third experience moderate to very severe discomfort after consuming alcohol. Only a few foods, such as cabbage, onions, and coffee, can compete with alcohol in contributing to IBS problems. But is it only the alcohol content that is the culprit in the drama?

Research has shown that different types of alcoholic drinks can have different effects on the gastrointestinal tract, with factors such as pH and other ingredients in the drink playing a significant role in the discomfort.

Effects on different parts of the gastrointestinal tract

To understand the effect alcohol has on your digestion, it may be necessary to better understand the effects that alcohol itself has on the different parts of the digestive tract.

Effects on the throat and esophagus

Regardless of the type or strength of the alcohol, the musculature in the esophagus and the sphincter (a valve) that separates it from the stomach get relaxed. This allows the gastric acid to travel up from the stomach to the throat, which is commonly referred to as acid reflux. It is the burning sensation that you feel after alcohol consumption. For those who already suffer from acid reflux, alcohol can therefore have a fairly immediate negative effect. After long-term alcohol consumption, the cells that line the esophagus can become severely damaged causing other complications.

Effects on the stomach

When alcohol reaches the stomach, the production of gastrin and gastric acid secretion are affected. Differences emerge between various alcoholic beverages, where fermented beverages such as wine, beer, and champagne increase acid secretion the most. The strong seasoning in mulled wine and similar beverages can reinforce the negative effect.

However, distilled beverages such as whiskey and brandy show no increase in gastrin and gastric acid production and may even inhibit acid secretion.

Effects on the intestines

The amount of alcohol can affect bowel movements, which is of particular relevance to people with IBS. A relatively low alcohol intake can increase bowel emptying and lead to diarrhea, while a high alcohol intake can instead reduce bowel movements and cause constipation. A study found that binge drinking (more than 4 drinks* per day) has been associated with many gastrointestinal symptoms while moderate to low drinking has a weak association.

Alcohol can also promote inflammation in the intestines which can further exacerbate the symptoms including abdominal pain.

Digestive tract

Effects on gut microbiome

Everyone has ‘good’ and ‘bad’ bacteria in their gut. Alcohol disrupts the normal balance causing an increase in the harmful bacteria. This contributes to inflammation and often leads to a ‘leaky gut’ which is often associated with IBS. In simple terms, ‘leaky gut’ refers to increased permeability of the intestines that enables harmful substances to enter the bloodstream. An increase in ‘bad’ bacteria can also trigger diarrhea, gas, and bloating. The lower the risk of bacterial imbalance, it is encouraged to increase the intake of probiotics, which are the ‘good’ bacteria found mainly in fermented food and as supplements.

More factors than the alcohol content

The alcohol itself thus has quite clear effects on different parts of the gastrointestinal tract and for drinks with high alcohol content such as distilled drinks (cognac, absinthe, vodka, whiskey, etc.), the alcohol content is perhaps the most decisive factor for how the gastrointestinal tract will react. However, understanding how alcoholic beverages fully affect the gastrointestinal tract is a more complex issue, with factors such as pH, other ingredients added, and the distillation process all playing a role. Whether it’s an alcoholic drink or not, keep in mind that factors such as seasoning, sweetness (sugar and sweeteners), carbonation, and pH (how acidic the drink is) may also negatively affect how the stomach reacts.

Advice on alcohol consumption

The simplest advice for people with IBS is the usual, to handle food and drink in moderation and balance, including alcoholic drinks. Especially when the holidays come and many people’s eating and drinking habits change drastically for a short period. Generally, the safe alcohol limits are no more than one drink* per day for women and no more than two drinks for men while having at least two alcohol-free days a week.

* A drink is defined as about:

  • 350 ml of regular beer (5% alcohol)
  • 150 ml of wine (12% alcohol), or
  • 45 ml of distilled spirit (40% alcohol)


Reding, K. W., Cain, K. C., Jarrett, M. E., Eugenio, M. D., & Heitkemper, M. M. (2013). Relationship between Patterns of Alcohol Consumption and Gastrointestinal Symptoms among Patients with Irritable Bowel Syndrome. The American Journal of Gastroenterology108(2), 270–276.

Cozma-Petruţ, A., Loghin, F., Miere, D., & Dumitraşcu, D. L. (2017). Diet in irritable bowel syndrome: What to recommend, not what to forbid to patients! World Journal of Gastroenterology23(21), 3771.

Engen, P. A., Green, S. J., Voigt, R. M., Forsyth, C. B., & Keshavarzian, A. (2015). The Gastrointestinal Microbiome: Alcohol Effects on the Composition of Intestinal Microbiota. Alcohol Research: Current Reviews37(2), 223–236.