Why am I bloated all the time? The patterns that matter

Most everyday bloating is gas with an ordinary cause: eating fast, constipation, a food your gut handles badly, IBS, or the time of the month. Around 4 in 10 people get bloated now and then. If it happens to you regularly, the NHS advice is to see a GP, whatever the cause.

I had bloating and constipation for years and assumed that was who I was. What I would tell you now is that the timing of bloating says more than the fact of it, and the rest of this page is about reading that timing.

What makes a tummy bloat in the first place?

Gas, usually, though not always more gas than anyone else has. Some of it is swallowed with food and fizzy drinks. Some is made in the large bowel, where bacteria ferment the parts of a meal you did not digest higher up, which is why beans, lentils, cabbage and onions have the reputation they do.

Two other things can make an ordinary amount of gas feel like a lot. In IBS the nerves of the gut can be too sensitive to the way the bowel normally moves, so a normal load registers as pressure or pain. And the swelling you can see is partly a reflex. In people who get visible swelling, the diaphragm tightens and pushes down while the belly wall relaxes, so the contents of the gut are pushed forward. A team in Barcelona caught this on CT scans in people who swelled up after eating lettuce: their waists grew by about 3.5cm without a significant rise in gas, and their diaphragms had dropped.

Bloating is the feeling of fullness or pressure. Distension is the visible widening. You can have either, or both, and the mechanisms behind them are not fully understood, which is why nobody can hand you a single answer from a description.

Which pattern sounds like mine?

Look at when it happens, not only how bad it is. These are the patterns worth noticing and what each one most often points to. None of them is a diagnosis.

Why is my stomach flat in the morning and swollen by teatime?

Because that is the usual shape of bloating, and on its own it is not a warning sign. People with bloating often say their stomach is flat when they get out of bed and grows with each meal. In a Manchester study that tracked waist size over 24 hours in 20 healthy women, girth was bigger at the end of the day than at the start, went up after a standard meal, and came down during sleep. Sitting and standing measured bigger than lying down, too.

So part of a bigger evening tummy is eating and being upright all day. What makes it worse is more in your hands: large meals, fizzy drinks, eating late and slouching over a plate are all on the NHS list of things that add to bloating. If yours runs the other way and is there from the moment you wake, read bloated in the morning before you have eaten anything, because that pattern deserves a closer look.

Could it be constipation if I go every day?

Yes. The NHS counts it as constipation if you have not been at least 3 times in the last week, or if your poo is dry, hard or lumpy, you are straining, or you feel you have not emptied your bowels. Feeling bloated comes with it. Going daily is not the test.

The usual causes read like a busy working life: not enough fibre or fluid, long periods sitting, a change in routine, stress, and often ignoring the urge to go. On the ward I learned to put off going to the toilet, and if you work shifts you may recognise that. The NHS suggests a regular time and place for the toilet, not delaying when you feel the urge, resting your feet on a low stool, a daily walk, plenty of fluids, and raising fibre gradually, because a sudden jump can make symptoms worse.

One thing to know: the NHS bloating page puts bloating that comes with constipation on its urgent list, below. If the two are new together, or not settling, ring rather than wait.

Is it something I am eating?

Sometimes, and timing is the clue. A food intolerance usually shows a few hours after the food, with bloating, wind, tummy pain or diarrhoea, and lactose, the sugar in milk, is the commonest one. Coeliac disease, an immune reaction to the gluten in wheat, barley and rye, also causes bloating. It affects at least 1 in 100 people in the UK, and milder cases can be mistaken for IBS.

The trap is cutting foods out on a hunch. Stop eating gluten before a coeliac blood test and the result will probably be inaccurate. Drop several foods at once and you can miss out on vitamins and minerals, which is why the NHS says not to cut foods out without advice from a GP or a dietitian.

What about bloating around my period?

It is common, and on its own it follows the calendar. Bloating or cramping is one of the most common symptoms of PMS, which comes in the weeks before a period. The NHS suggests a diary of symptoms for at least 2 menstrual cycles, and that is the only way to see whether your bloating rises and falls with your cycle or ignores it. I have set out how to do that in period bloating or gut bloating.

When does bloating all the time need a GP?

When it is regular, when diet changes have not helped, or when other symptoms come with it. These are the NHS’s own lists for bloating.

See a GP if:

• “you feel bloated regularly”
• “you’ve tried changing your diet but keep feeling bloated”
• “you have bloating and unintentional weight loss”
• “you have bloating and also have blood in your poo”

Ask for an urgent GP appointment or call 111 if:

• “you have bloating with vomiting (being sick), diarrhoea or constipation”
• “you have bloating with a stomach ache”
• “you have a high temperature (fever), or feel hot, cold or shivery”
• “you have a swelling or lump in your tummy”
• “you cannot pee, poo or fart”
• “you have a burning feeling in your chest caused by stomach acid travelling up towards your throat (acid reflux)”

Call 999 or go to A&E if you have bloating with a swollen stomach and:

• “you have a stomach ache that is severe and came on very suddenly”
• “you’re vomiting blood or your vomit looks like ground coffee”
• “you have severe difficulty breathing”

If you have ovaries, know one more. Having a swollen tummy or feeling bloated frequently, roughly 12 or more times a month, is one of the main symptoms of ovarian cancer. Those symptoms are common and have many causes, and that is exactly why a GP should look rather than you guess.

How do I work out which pattern is mine?

Write it down for a week before you change anything. Note what you ate and when, how fast, what you drank, when the bloating started and how bad it was, your poo, your sleep, your stress and the day of your cycle. A dated record turns “it’s always bad” into something a GP can work with, and the gap between eating and bloating tells you whether to look at the last meal or one from hours earlier.

After that, change one thing at a time so you can see what helped. If you would like a quicker steer first, the bloating quiz is six questions and suggests a sensible next step. And if yours has gone on for weeks without shifting, read bloating that will not go away before you try anything else.