Bloating, cramps or an upset stomach after milk, cheese or cream? Dairy is one of the most commonly suspected food triggers — and one of the few where testing can give you a genuinely clear answer. The key is knowing which of three different problems you're dealing with, because the tests (and the fixes) are completely different. The Vesey Private Hospital in Sutton Coldfield offers GP-led assessment from £90 with same-week appointments, 7 days a week.
Three Different Dairy Problems
Lactose intolerance — the most common by far. Your gut makes too little lactase, the enzyme that digests milk sugar; undigested lactose ferments in the bowel causing bloating, wind, cramps and diarrhoea 30 minutes to 2 hours after dairy. It's dose-dependent: many people tolerate a splash of milk but not a milkshake, and hard cheese and butter (very low lactose) often cause no trouble at all.
Cow's milk protein allergy — an immune reaction to milk proteins (casein, whey), mostly seen in infants and usually outgrown; genuine new milk allergy in adults is rare. Symptoms can include hives, swelling, vomiting or wheeze soon after dairy.
Secondary lactose intolerance — temporary lactase loss after gastroenteritis, or caused by an underlying gut condition such as coeliac disease or Crohn's. This one matters because treating the underlying condition can restore your dairy tolerance — and because it's the diagnosis mail-order tests never make.
Which Tests Give a Reliable Answer
Structured exclusion and reintroduction — 2 weeks strictly dairy-free (watching for hidden lactose in sauces, bread and medication), then reintroduce and observe. Symptoms that resolve then return on reintroduction give a clear practical diagnosis. Simple, free, and reliable when done properly.
Hydrogen breath test — after a lactose drink, breath hydrogen is measured over 2–3 hours; a rise confirms lactose malabsorption. Useful where exclusion trials are equivocal.
Specific IgE blood or skin-prick testing — appropriate only where the history suggests true milk allergy (rapid-onset hives, swelling, wheeze). What to skip: IgG dairy 'sensitivity' tests and hair testing — neither can diagnose dairy intolerance, whatever the report claims.
One important check first: symptoms triggered by dairy overlap heavily with coeliac disease and IBS, so a coeliac blood test (from £32) is worthwhile before you settle on lactose as the answer — especially if you also react to bread and pasta.
Living Without (Much) Dairy
Most lactose-intolerant people don't need to give up dairy entirely. Strategies that work: smaller portions spread through the day, lactose-free milk (identical nutrition, lactose pre-digested), hard cheeses and butter, live yoghurt (the cultures digest much of the lactose), and lactase enzyme tablets before meals out.
If you do cut dairy substantially, plan your calcium and vitamin D — dairy is the main UK source, and long-term low calcium intake matters for bone health, particularly for women approaching menopause. A dietitian can make sure the numbers add up; fortified plant milks, tinned fish with bones, tofu and leafy greens all contribute.
Getting Tested at The Vesey
A GP appointment (from £90) sorts the three dairy problems apart, screens for coeliac disease and other mimics, and sets up a proper exclusion trial with a dietitian where needed. Allergy testing is arranged where the history points to true milk allergy.
Same-week appointments, results in 24–48 hours, free parking, open 7 days 8am–8pm. Book online or call 0121 387 3727.
Reacting to dairy? Get a clear answer, not a guess
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Frequently Asked Questions
How do I know if I'm lactose intolerant or allergic to milk?
Timing and symptoms differ: lactose intolerance causes digestive symptoms (bloating, wind, cramps, diarrhoea) 30 minutes to 2 hours after dairy and depends on the amount eaten. Milk allergy causes rapid-onset symptoms like hives, swelling or wheeze and is rare in adults. A GP can usually tell from the history alone.
Is there a blood test for lactose intolerance?
Not a direct one. Lactose intolerance is confirmed by a structured dairy exclusion and reintroduction, or a hydrogen breath test. Blood tests are still useful to exclude coeliac disease, which commonly masquerades as dairy intolerance. Avoid IgG 'dairy sensitivity' tests — they are not diagnostic.
Can lactose intolerance start suddenly in adulthood?
Yes. Lactase production naturally declines with age in most of the world's population, and a bout of gastroenteritis, coeliac disease or gut inflammation can trigger secondary lactose intolerance at any age — sometimes reversibly, if the underlying cause is treated.
What does dairy intolerance testing cost at The Vesey?
GP assessment is from £90 and blood tests (including coeliac screening) from £32, with results in 24–48 hours. Dietitian-supervised exclusion programmes and allergy testing are available on site in Sutton Coldfield, with no referral needed.