Booze and poos! What alcohol does to your digestive system!

As we enter the party season, it’s worth taking a quick look at the way in which alcohol affects your digestive system, and some of the steps you can take to reduce those effects.

Anyone who’s ever had a few too many at the office party will be familiar with the morning after feeling. More often than not, this involves rather unpleasant diarrhoea, but it can also lead to constipation too. But why does booze affect our poos in this way?

Speeding throughAlcohol and your gut

Alcohol will increase the speed at which everything moves through your digestive tract, all the way from your stomach to your colon. This means that your stomach will empty too quickly into the small intestine, and the digestive waste will move too fast through the large intestine for all of the water to be reabsorbed. Add in the fact that you are probably consuming more fluid than normal when you’re out drinking, and it’s easy to see how your stools can become loose and watery. This rapid movement of the digestive tract can also have the unpleasant side effect of making your need for the loo feel very sudden and urgent.

Please note that while diarrhoea the day after drinking is common, if this persists for more than 48 hours, you should seek medical attention.

If your stomach empties too quickly, it can release undigested carbs into your small intestines, which could feed the unwelcome mircrobes and cause an imbalance in your gut flora. This isn’t a problem for the occasional party, but it can become an issue for regular drinkers, causing a condition called SIBO or small intestine bacterial overgrowth.

Drying up

For some people, alcohol can have the opposite effect, drying up the stools and causing constipation. Even though you are drinking more than usual, alcohol is a diuretic, so you will actually produce more urine than you are taking in in fluid, leaving you dehydrated. This excessive urination can also cause the loss of essential electrolytes, such as sodium and potassium, which are needed to retain fluid, both in the body and in your stools. This is why you wake up with a dry mouth and a killer thirst, even when you have drunk several pints the night before.


Sometimes, it may not be the alcohol that is causing the problems at all; you may simply be intolerant or allergic to the non-alcohol components of your drinks. The gluten within the wheat and barley used to make beer is a common culprit, as are the tannins in grape skins. If you feel that your gut is reacting disproportionately to the amount you are drinking, it may be worth having a food intolerance test. Many ARCH registered therapists now offer Lorisian Food Intolerance testing at their clinics.

Similarly, if you already have problems with your gut, such as IBS, then alcohol can often irritate this, causing your symptoms to get much worse. So if you often get an extreme gut reaction to alcohol, then you should talk to your doctor, as this may be an indicator of an underlying digestive health issue.

Preventing problems

There are several steps you can take to avoid the gut problems associated with alcohol, without spoiling the Christmas party. Here are some top tips:

  • Make sure that you are well hydrated in advance of your night out by drinking plenty of water, preferably mineral water.
  • Drink this on an empty stomach if you can, to maximize absorption.
  • Interspace your alcoholic drinks with water through the evening, both to stay hydrated and cut down your overall consumption.
  • Eat something before you start drinking. A full stomach will absorb less alcohol, and is also less likely to empty prematurely.
  • Add salt to your meal to help maintain your electrolyte balance.

However you plan on celebrating, we wish you a very merry Christmas from everyone at ARCH. Cheers!





Leave a Reply