Beer bloats you three ways: carbonation fills your gut with gas, alcohol irritates the gut and slows emptying, and the fermentable wheat carbs feed gas-producing bacteria.
The NHS lists fizzy drinks and alcohol among bloating causes and advises against lots of either late at night. Smaller pours, slower pace, water between beers, and no pre-bed pints all help. If one or two beers reliably blow you up while other drinks do not, test a gluten-free beer. Frequent, severe, or persistent bloating regardless of beer, especially with bowel changes, weight loss, blood, or vomiting, is the GP version.
What to do
Common questions
Why does beer make me bloated?
Beer is a triple hit to your gut. First, carbonation: you are drinking gas, and the NHS lists fizzy drinks among the causes of the most common kind of bloating, which is a lot of gas in your gut. Second, alcohol itself, which the NHS also lists on its bloating don't-drink-too-much list, irritates the gut and slows the stomach emptying that would move things along. Third, the volume and ingredients: a pint is half a liter of fluid plus fermentable wheat and barley carbs that gut bacteria feast on, producing yet more gas, and salty bar snacks add water retention on top. The fixes are dose and pace: smaller pours, slower drinking, alternating with water, and skipping the pint-before-bed habit, since the NHS also advises against large meals or lots of drinking late at night for bloating. If even one or two beers blow you up reliably while other alcohol does not, consider the wheat angle and try a gluten-free beer for comparison. See a GP if bloating is frequent, severe, or persistent regardless of beer, especially with changed bowel habits, weight loss, blood in your stool, or vomiting, because the NHS's rule is that regular bloating that does not go away deserves checking.