When things slow down, every meal becomes a suspect — and because your gut answers for what you ate a day or two ago, guesswork gets you nowhere. This page is about exploring those patterns properly, through a structured elimination — not about a quick fix.

What this screen is — and what it is not

What it is

• A straightforward way to explore which foods you might trial when looking at your own bowel regularity
• A non-invasive 700+ item hair test that flags foods to consider, giving you a shortlist for a structured elimination
• A 6-week core elimination plan with a food diary, then a structured reintroduction one food at a time, to see whether removing certain foods makes a difference for you
• Personal discovery — over the process you build your own picture of which foods seem to suit you
• A 700+ item hair screen that flags foods to trial first — informed by general reading on how fibre, fluid and very processed foods relate to bowel function (that’s background, not validation of the test)

What it is not

• A medical test, a diagnosis, or a way to treat any bowel condition
• A replacement for seeing your GP if your symptoms persist, change suddenly, or get worse
• An IgE allergy test — it does not detect allergic antibodies
• A coeliac test or a lactose-intolerance test
• A measure of your fibre, hydration, bowel transit time, stool or gut bacteria — the hair test measures none of these and cannot identify a medical cause
• A promise that constipation will resolve — some causes are medical and need professional care

How Food Choices Can Affect Bowel Movement

Lots of everyday things shape your bowel rhythm: fibre adds bulk to stool and helps the colon move waste along; water keeps stool softer and easier to pass; the bacteria in your gut help set the pace; and your routine, activity, sleep and stress all play a part. Diet is only one piece, but it’s a piece you can experiment with. Some people find that eating mostly low-fibre, heavily processed foods — white bread, processed meats, lots of fried takeaway — seems to leave them feeling more sluggish, while a wider range of whole foods and enough fluid seems to suit them better. Others notice particular foods, such as a lot of dairy, appear to coincide with harder, less frequent movements. The honest position is that everyone is different, and the only way to learn your own pattern is to test it. That’s where a structured elimination comes in: you remove a small set of suspected foods for a while, watch what happens, then add them back one at a time. Any change you notice comes from that process of removing, observing and reintroducing — from stepping away from foods that seem to cause you friction — not from a ‘magic food’ and not from the test itself. Importantly, the hair panel does not measure your fibre intake, your hydration, your bowel transit time, your stool, your gut bacteria, or any medical cause of constipation. It simply gives you a shortlist of foods to consider trialling. The learning happens in the elimination, in your kitchen and your diary — not in the lab.

Does this sound like you?

• Infrequent bowel movements (fewer than 3 times per week)
• Stools that are hard, dry, or difficult to pass
• Feeling like you haven’t fully emptied your bowels after going
• Needing to strain during bowel movements
• Bloating or discomfort in your abdomen
• Loss of appetite or feeling uncomfortably full quickly
• Noticing a pattern: your bowels seem more sluggish after certain foods

Related foods worth checking at the same time

• Processed meats (often eaten in low-fibre meals, and some people link them to harder, less frequent stools)
• Refined grains and white bread (low in fibre)
• High-fat dairy products (some people notice a difference when they cut back)
• Fried and heavily processed foods (often low in fibre and short on vegetables)
• Low-fibre takeaway meals (refined carbs and not much veg)
• Plenty of caffeine with not much water alongside (can leave some people less hydrated)

Examples of what the 700+ item panel covers

• Cow’s milk
• Cheese (cheddar, mozzarella, blue)
• Yoghurt
• Wheat
• Rye
• Barley
• Oats
• Eggs
• Processed and cured meats
• Beef
• Pork
• Refined and heavily processed foods

How to run a focused elimination

Plan for The 6-week core plan: a structured elimination with a food diary, then a gradual reintroduction one food every 3–5 days afterwards.

1. Day one: start your food and symptom diary — what you eat, your fluids, and your bowel pattern. The 90-day money-back guarantee asks you to follow your plan for at least 6 weeks with a food diary, so begin it straight away. Use the first few days to note your top suspects (for example, ‘a lot of dairy seems to leave me sluggish’).
2. Weeks 1–2: remove your main suspected foods, using your 700+ item Gold panel shortlist as the starting point. Build meals around whole foods: lean proteins, fresh vegetables, whole grains, and enough fluid (roughly 1.5–2 litres of water a day). If you’ve been eating very little fibre, increase it gradually rather than all at once.
3. Weeks 3–6: keep the shortlisted foods out and let your rhythm settle to what’s normal for you. Bowels respond slowly, so give the full core plan time — a settled fortnight in your diary tells you more than any single good day.
4. Afterwards — reintroduce one removed food every 3–5 days in small amounts and watch whether anything changes. This is what shows you which foods genuinely affect you, rather than which ones you simply suspected.
5. Beyond the plan: use what you’ve learned to shape your eating long-term. Some people stay off a food entirely; others find small amounts are fine. Your own response is the guide — and if symptoms persist, that’s a reason to see your GP rather than keep restricting.

The reintroduction phase is the part that actually teaches you something, because it helps you separate coincidence from a real pattern and find your own tolerance levels. You might discover you can have a little of a food but not a lot, or that it sits fine on some days but not others (often alongside stress, poor sleep, low fluid, or what else you ate that day). That’s completely normal — bowels respond to far more than food alone. Write your findings down as you go so you can make calm, informed choices instead of living by strict rules. And remember the point of the exercise is a wider, comfortable diet, not a long list of bans: if your reintroductions don’t explain your symptoms, that’s useful information too, and a sign to talk to your GP.

One customer’s experience

Joanne, 47, had felt sluggish and backed up most days for as long as she could remember, with infrequent, uncomfortable bowel movements. She’d already tried drinking more water and eating more fibre, and it helped a little, but she still wanted to understand her own patterns — and guessing was hopeless, because her gut seemed to answer for meals a day or two after she’d eaten them. She used a £49 hair screen to choose a shortlist of foods to trial, then ran the structured 6-week plan: shortlisted foods out — including a lot of her usual dairy — with a diary kept from day one. Over those weeks her regularity settled and she felt less bloated. Reintroducing foods one at a time afterwards showed her which changes had actually mattered, and which she could relax about. The way Joanne tells it, there was nothing magic about the test: it was the patient work of removing foods, watching, and adding them back that taught her what suited her. The screen just spared her months of changing everything at once.

Common questions

How is constipation different from other digestive issues?

Constipation usually means infrequent or difficult bowel movements — stools tend to be hard and dry, and you may feel you haven’t fully emptied. That’s different from bloating (feeling full or tight) or from loose, frequent stools. In practice these can overlap, so plenty of people notice constipation and bloating together. Our screening doesn’t tell you what’s wrong; it simply gives you a shortlist of foods you might trial removing and reintroducing to see whether they’re part of your own pattern.

Should I just add more fibre if I’m constipated?

Not necessarily — and adding a lot too quickly can backfire for some people. Fibre needs fluid to do its job, so without enough water it can feel more uncomfortable, not less. Some people also find their pattern eases when they step away from particular foods, without piling on extra fibre at all. A sensible starting point is steady hydration (around 1.5–2 litres of water a day) and a good range of whole foods, while you watch your pattern. If you do add fibre, build it up slowly over a week or two and drink plenty alongside. The elimination process is just a structured way to see what suits you.

Can dairy really affect constipation for some people?

Some people do notice a difference when they cut back on dairy, and others notice nothing at all — it really varies. Dairy is low in fibre, and a diet heavy in it can mean less room for fibre-rich foods, which may be part of the picture for some. We can’t tell you in advance whether dairy is an issue for you; lactose intolerance, for instance, more often goes the other way and causes loose stools rather than constipation. The 700+ item Gold panel simply flags dairy as one food you could trial removing and reintroducing, so you can judge from your own experience rather than guesswork.

Is constipation ever a sign something serious is wrong?

Occasional constipation is very common and often linked to diet, fluid, activity or routine. But if you notice a sudden or persistent change in your bowel habit — especially with blood, severe pain, unexplained weight loss, or symptoms lasting more than a couple of weeks despite dietary changes — please speak to your GP. They can check for medical causes. Our screening is only designed to help you explore food patterns through an elimination; it is not designed to identify or rule out any medical condition.

How long before I might notice my pattern changing?

It varies a lot from person to person. Some people notice a shift within a week or two of removing a food; for others it takes longer, and for some, food turns out not to be the main factor at all. Your gut also takes time to settle to any change in diet. That’s why the plan runs as a 6-week core elimination with a food diary, followed by a careful reintroduction one food at a time — and it’s why the 90-day money-back guarantee asks you to follow your plan for at least 6 weeks with a food diary, started on day one. Any change you notice comes from changing your diet and observing — not from the test itself. If nothing settles over that time, that’s a useful result too, and a good moment to see your GP.

Can the IntoleranceLab screen identify coeliac disease or lactose intolerance?

No. Our hair screen checks your sample across the 700+ item Gold panel to give you a shortlist for an elimination. It is not an IgE allergy test, and it is not designed to identify coeliac disease or lactose intolerance. If you think you may have coeliac disease, you’ll need a blood test from your GP (and you must still be eating gluten when tested). If lactose intolerance is suspected, your doctor can arrange a hydrogen breath test. Our screening sits alongside medical testing — it doesn’t replace it — by helping you explore which foods you might trial through the elimination process.

Are there foods people often add for regularity?

Briefly, and as background only — this isn’t what your report flags. People commonly reach for prunes, berries, whole grains and plenty of water. But adding foods is guesswork; the value here is knowing which foods to take OUT first — that’s what your shortlist gives you, so you trial your own small set rather than copying a generic list.

If I’m constipated, does that mean I’m reacting to everything I eat?

Almost certainly not. Constipation has many possible causes — not enough fluid, low activity, certain medications, a low-fibre diet, routine, and sometimes particular foods among them. Our panel flags your individual shortlist, and many people end up trialling only a small handful of items from their report. The elimination process is about stepping away from that small set, watching what happens, then eating a wide range of whole foods without worrying. You’re not avoiding everything — you’re narrowing things down to what actually matters for you.

Why might the same food seem to affect me on some days but not others?

Because your bowels respond to much more than food. Stress, sleep, activity, your menstrual cycle (if that applies to you), and the other meals you’ve eaten all feed into it. A food that sits fine on a relaxed Sunday might feel different on a hectic Monday when you’ve also skipped water and barely moved. That’s exactly why the protocol leans on a full symptom diary — over time you start to see the bigger picture rather than blaming one food. Many people realise their reaction depends as much on stress or tiredness as on the food itself, which is genuinely useful to know.

Related reading

• Exploring Dairy Intolerance
• Understanding Histamine in Foods
• Gluten and Digestive Symptoms
• Bloating: When Foods Cause Discomfort