By mid afternoon your waistband is tighter than it was at breakfast, and by evening you look four months pregnant. You have cut out gluten, bought the probiotic, and nothing much changed. Bloating is one of the most searched symptoms on the internet and one of the most poorly explained, partly because the word covers two different things that have different causes.
Bloating is the feeling. Pressure, fullness, tightness. It is driven as much by how sensitive your gut nerves are as by how much gas is in there.
Distension is the measurement. Your abdomen is visibly bigger and your clothes do not fit the way they did this morning.
Plenty of people have one without the other, and the distinction matters. Someone whose belly is visibly larger by evening is usually dealing with gas, transit or the muscles of the abdominal wall. Someone who feels intensely bloated with no visible change is usually dealing with a gut that reports normal sensations too loudly, which is the hallmark of irritable bowel syndrome and does not respond to the same fixes.
Constipation. This is the one people skip because they assume constipation means not going at all. Incomplete emptying, hard stools, or going every third day will produce exactly this pattern: fine in the morning, enormous by night. It is the single most common reversible cause and the first thing worth fixing.
How you eat, not just what. Eating quickly, talking through meals, fizzy drinks, chewing gum and drinking through straws all deliver air into your gut. Large evening meals after a day of barely eating guarantee the worst of it lands at bedtime.
Fermentable carbohydrates. Onions, garlic, wheat, pulses, apples, stone fruit and sugar free sweeteners ending in ol are fermented by gut bacteria and produce gas. This is normal digestion, not disease. A short, properly structured low FODMAP trial can identify which ones matter for you, but it is a diagnostic exercise of a few weeks with a dietitian, not a diet to live on. Long term restriction narrows your microbiome and tends to make you more sensitive, not less.
Lactose intolerance. Common worldwide, more common in people of East Asian, South Asian, African and Middle Eastern ancestry, and it often arrives in adulthood rather than being lifelong.
Irritable bowel syndrome. Bloating with a change in bowel habit, pain that eases after passing a stool, symptoms that flare with stress. IBS is a positive diagnosis, not a label applied after everything else is excluded, and it responds to a specific set of treatments.
Coeliac disease. Important, missed often, and worth testing for rather than guessing. The crucial practical point: the blood test only works if you are still eating gluten regularly. If you cut it out first, you can end up with years of uncertainty. Test first, then trial.
Medicines. GLP-1 drugs for weight and diabetes slow stomach emptying on purpose, and bloating, fullness and reflux are among their most common side effects. Iron tablets, some antidepressants, opioid painkillers and certain blood pressure medicines all slow transit too. We go through the GLP-1 side effect profile in our guide to how these drugs work.
Hormonal cycling. Progesterone slows gut transit, which is why many women bloat predictably in the second half of the cycle, and why bloating often becomes less predictable in perimenopause. If that is landing alongside other changes, the symptoms most often missed in perimenopause is the better starting point.
Pelvic floor and abdominal wall mechanics. A real and under recognised cause. In some people the diaphragm pushes down and the abdominal wall relaxes outwards in response to normal gut volumes, which produces dramatic visible distension with no increase in gas at all. It responds to physiotherapy and breathing retraining, not to dietary restriction.
Small intestinal bacterial overgrowth is real and worth testing in specific situations, typically after bowel surgery, in diabetes with nerve involvement, or in scleroderma. It has also become a catch all explanation sold alongside expensive protocols. Breath testing is imperfect and over diagnosis is common. Leaky gut, as marketed, is not a diagnosis you will find in a gastroenterology clinic. Be sceptical of anyone who diagnoses either from a questionnaire.
Change one thing at a time and write it down, because memory reconstructs patterns that were never there.
Keeping that log in one place matters more than people expect. If this ends up in a GP appointment, two weeks of recorded pattern changes the consultation entirely, which is what the symptom journal and timeline in a Health Passport is built for.
Most bloating is benign. These are the exceptions, and they deserve an appointment rather than another elimination diet:
Reasonable first line tests include a full blood count and ferritin, coeliac serology while you are still eating gluten, thyroid function, and a stool test for inflammation such as faecal calprotectin where inflammatory bowel disease is a possibility. For a woman with persistent bloating, a CA125 blood test and a pelvic ultrasound are the standard next step. Bring your two week log and say plainly how long this has been going on, because duration is the detail that decides which path your doctor takes.
If you want to organise your symptoms before that appointment, a symptom check will walk through timing, triggers and red flags in a structured order and give you something to hand over rather than a vague description.
Bloating after meals is usually constipation, eating pattern, fermentable carbohydrates, a medicine you are already taking, or a sensitive gut, and most of it improves with unglamorous changes made one at a time. The exception that matters is bloating that is present on most days for three weeks or longer, especially after 50, which is worth a blood test and a scan rather than another diet.
This article is for general education and is not a substitute for professional medical advice. Persistent bloating, unexplained weight loss or bleeding should be assessed by a qualified clinician.
Flu arrived early this year and four viruses are now circulating at once. What the pattern of your symptoms can tell you, what it cannot, and the few situations where knowing which one you have actually changes what happens next.
Norovirus season starts in October and the GII.17 strain most people have no immunity to is still dominant. How to tell a winter vomiting bug from food poisoning, how long you stay infectious, and why hand sanitiser does nothing.
Every October the same thing happens: the evenings close in and the energy goes. Where ordinary winter sluggishness ends and seasonal affective disorder begins, what the evidence says actually works, and the four conditions worth ruling out first.