Functional colopathy: understanding irritable bowel and avoiding aggressive cures (1/2)

You have a sensitive gut. Maybe a doctor has told you it's "irritable bowel syndrome," maybe you just know it as a touchy stomach that runs your day. The name changes, the daily reality stays the same: bloating, pain, a transit that does whatever it wants, and that fatigue that clings to you. I know how draining it is.

Irritable bowel syndrome is best managed with your doctor: under supervision, you cut back on the fermentable sugars that irritate the gut (the famous FODMAPs), you take stress into account, and you steer well clear of the aggressive "detoxes" that only irritate an already sensitive gut. That's what recent science shows. But no dietary idea replaces a doctor's follow-up: it works alongside it.

In this first part, I explain what's really going on in your gut, why classic detoxes are a bad idea for IBS, and which lifestyle habits are worth discussing with your doctor. Part 2 (coming soon) will dig into the low-FODMAP diet and living foods in detail.

What is irritable bowel syndrome (IBS)?

Irritable bowel syndrome (IBS) is a chronic functional disorder of the colon, with no lesion visible on standard tests. The word "functional" says it all: your gut works poorly, but endoscopy and lab work show nothing abnormal. That doesn't mean it's "all in your head." It means the problem is in how things work, not in the structure.

And it's anything but rare. IBS affects an estimated 5 to 10% of adults worldwide, with women diagnosed roughly twice as often as men. It also accounts for a large share of gastroenterology visits. So if you've been suffering in silence, you're in very large company.

That's exactly why I wanted to write this. Too many people think they just have to "live with it," without trying anything. Not true. IBS is managed with your doctor; here is what is known today. As long as you understand what's happening.

The symptoms that wreck your day

You probably know them by heart. Let's name them anyway, because that helps. The most common signs of IBS:

• Abdominal pain: cramps, spasms, a twisting feeling, often relieved after a bowel movement.
• Bloating: a belly that swells over the day, until you feel "full" and tight.
• Bowel changes: diarrhea (IBS-D), constipation (IBS-C), or alternating between the two (IBS-M, "mixed").
• Gas and gurgling: intestinal fermentation you can actually hear.
• Urgency and incomplete evacuation: that anxiety of needing a toilet, fast.

On top of that come symptoms we talk about less: chronic fatigue, broken sleep, anxiety, sometimes headaches. The most exhausting part? The unpredictability. You're fine for three days, then a meal, a worry, and it all comes back. That constant uncertainty wears down your mind as much as your body.

The mechanisms: why your gut overreacts

There isn't one cause of IBS. There's a cluster of mechanisms that stack up. Here they are, without the jargon.

Visceral hypersensitivity. This is the heart of the problem. Your gut reads as painful the kind of signals another person wouldn't even feel. Picture a volume dial turned up too high: a normal sound becomes unbearable. That's exactly it, but for the sensations in your belly. The cause: scrambled communication along the gut-brain axis.

Motility problems. Your colon contracts too fast (diarrhea), too slowly (constipation), or chaotically. Hence the spasms.

Microbiome imbalance (dysbiosis). Too many gas-producing, fermenting bacteria, not enough protective ones. This imbalance can follow a course of antibiotics, a low-fibre diet, chronic stress, or a bad bout of gastroenteritis, that's "post-infectious" IBS, affecting roughly 10% of cases.

Low-grade inflammation. Invisible on tests, but present in the mucosa of many people with IBS. It keeps symptoms going and weakens the gut barrier.

FODMAP sensitivity. FODMAPs are fermentable sugars found in a huge range of foods (onion, garlic, apple, wheat, milk, legumes, cruciferous vegetables). Poorly absorbed, they ferment in the colon, produce gas and water, and trigger symptoms. An estimated 75% of people with IBS are sensitive to them. More on this below.

Stress. Not the single cause, but a major amplifier. Your gut and brain talk constantly through the vagus nerve. Stress disrupts motility, increases permeability, and stokes inflammation. And an irritated gut sends back signals that feed anxiety. A vicious circle, in short.

You see the picture. A tangle of interwoven factors. That's precisely why there's no single fix, and why a standard "detox," which addresses none of them, can do more harm than good. Let's talk about that.

Why aggressive "detoxes" make IBS worse

Classic detox cures are designed for "ordinary" guts, not for a hypersensitive irritable bowel: they over-stimulate it, throw the microbiome further off balance, and weaken the mucosa. The result is that they often worsen the very symptoms you hoped to calm. If you've ever tried a "miracle" detox juice and ended the day doubled over, you know what I mean.

It's not your fault. The method just wasn't suited to you. Here are the ones to be wary of.

The methods to avoid

• Raw fruit and vegetable "detox" juices: concentrated in fructose and FODMAPs (apple, pear, mango), or in raw cruciferous veg (cabbage, broccoli). A fermentation bomb for a sensitive gut.
• Lemon water on an empty stomach: very acidic, often spiked with cayenne. On an already irritated mucosa, that's pouring fuel on a fire.
• Stimulant laxatives (senna, cascara): they trigger violent contractions. On an already hyperreactive colon, that's a guarantee of cramps, and, over time, dependence.
• Enemas and colon hydrotherapy: flooding the colon with water to "scrub" the walls. Appealing in theory. In practice, risk of cramps, a washed-out microbiome, and rare but serious complications. Not to be done on your own.
• Prolonged water fasting: starving the gut for days can weaken the barrier and starve the good bacteria, with a sometimes brutal rebound when you start eating again.
• Activated charcoal or chlorella at high doses: charcoal absorbs everything, including your nutrients and medications. Chlorella, above 10 g/day, can cause bloating and gas in sensitive people. For IBS, talk to your doctor first, and never make it a "shock cure."

I'm not demonizing anything. I'm simply saying: for IBS, these head-on approaches miss the mark. Gentle intermittent fasting (skipping a meal) may suit some people; senna, never. Nuance.

Why these cures worsen IBS

The logic is simple, once you understand the mechanisms. These detoxes ignore the hypersensitivity (they stimulate where you should soothe). They wash out an already fragile microbiome. They increase gut permeability. And they impose physiological stress, and stress, as we saw, triggers flares. In short, they tick every wrong box.

So what do we do? We flip the mindset completely. We stop trying to "purge." We move forward patiently, with your doctor's input.

FODMAPs and IBS

A low-FODMAP approach means temporarily cutting back on the fermentable sugars that feed IBS symptoms, then reintroducing them one by one to pinpoint your personal triggers. It is, to date, the best-documented dietary approach for IBS. But it's best done with a dietitian, because poorly run, it impoverishes the diet.

And the evidence is solid. A meta-analysis of randomized controlled trials showed that a low-FODMAP diet clearly reduces IBS symptom severity compared with a standard diet. A network meta-analysis published in 2025 in The Lancet Gastroenterology & Hepatology ranks dietary interventions among the most effective strategies, with the low-FODMAP diet at the top. This isn't a fad. It's validated.

IBS: what to eat

In practice, during a soothing phase, here's what usually goes down well (everyone has their own threshold, so observe yourself):

• Gentle proteins: firm tofu, tempeh, pumpkin and sunflower seeds.
• Well-tolerated starches: rice, quinoa, potatoes, sweet potato, gluten-free sourdough bread.
• Cooked vegetables: carrot, zucchini, squash, spinach, green beans (cooking softens them enormously).
• Low-fructose fruit: ripe banana, blueberry, strawberry, kiwi, orange (in moderation).
• Good fats: olive oil, a little avocado, plant-based omega-3s (coming up).

Foods to limit (at least while you soothe)

• Dairy (lactose), and gluten for sensitive people.
• Large amounts of legumes (lentils, chickpeas, kidney beans).
• Onion, garlic, leek, shallot, high in fructans.
• Raw cruciferous veg (cauliflower, broccoli, Brussels sprouts) and mushrooms.
• High-fructose fruit (apple, pear, mango, cherry, watermelon) and polyol sweeteners (sorbitol, xylitol).

I know, that's a lot of "no." But keep this in mind: it's temporary, and the goal is not to eat sadly for life. It's to identify your triggers so you can then widen your plate as much as possible. We add, we don't subtract for the sake of subtracting. Diversity stays the goal.

Lifestyle habits, alongside your medical care

What follows is neither a protocol nor a treatment. These are lifestyle habits, always to be checked and tailored with your doctor, gastroenterologist or dietitian. I'll insist: go gradually, at your own pace, watching how you react. There's no failure, only experiments.

Habit 1: at the table

A few concrete guidelines:

• Chewing: chew thoroughly, 30 times per mouthful if you can. It sounds silly. It really isn't: digestion starts in the mouth.
• Sprouted seeds, kefir and miso: sprouting and fermentation transform the food before the meal.
• Meal rhythm: leave 3 to 4 hours between meals, and avoid constant snacking, to let the stomach empty.

Habit 2: fats

Plant-based omega-3s. Flaxseed oil (one tablespoon, about 10 to 15 ml a day, never heated and kept cold), ground chia or hemp seeds, camelina oil. Flaxseed oil is the one I use on my salads, for my part.

Turmeric, with a pinch of pepper. Start small: a knife tip in a cooked dish, always with a little fat and a pinch of black pepper (which markedly improves curcumin uptake). Increase only if you tolerate it well. Never on an empty stomach, never in mega-doses on a fragile mucosa.

Psyllium husk. It is a soluble fibre; if your doctor advises it, always take it with at least 250 ml of water. Start with a teaspoon diluted in a large glass of water, and increase slowly. Golden rule: always at least 250 ml of water, or you get the opposite effect.

Habit 3: fermented foods

Gentle fermented foods, very gradually. Not raw sauerkraut or spicy kimchi to begin with. Start with a spoonful of kefir, then build up over several days if all goes well. Kefir, miso diluted in a soup: living sources of microorganisms.

Probiotics: not all strains are equal, and the choice of a product is made with your doctor or practitioner, rather than at random off the shelf.

Plant diversity. Vary plant foods over the week: think of it as a rainbow of shades on your plate. Aim wide, but go in stages, cooking foods at first. Sprouted seeds, gentle, are a lovely way in, more on that in part 2.

What a soothing day looks like: sample meals

Lists of foods are useful, but they often leave you staring at an empty plate. Here are three concrete days, built on the principles above, to adapt to what you personally tolerate.

Morning, without stirring things up

This is the trickiest meal, because the gut is just coming out of the night. A porridge of rice or buckwheat flakes cooked in water, a well-ripened banana, a spoonful of almond butter: that's a base most irritable guts tolerate. Drink: a chamomile or fennel infusion rather than a strong coffee on an empty stomach, which speeds up transit in many people.

At midday, the most substantial meal

This is when digestion is at its most efficient, so make the most of it. A base of rice, quinoa or potatoes, a portion of simple protein, cooked rather than raw vegetables, carrot, seedless courgette, spinach, green beans. A drizzle of raw olive oil at the end. Raw vegetables come back later, once the terrain has calmed down; they're not forbidden, just more demanding.

Evening, light and early

The single most cost-effective rule of all, and the most often ignored. A light dinner, eaten at least three hours before bed : a well-blended vegetable soup, a little rice, an unsweetened fruit compote. A heavy evening meal asks the gut to work right when everything else is slowing down.

Staying on course: the 80/20 rule

There always comes a moment when you feel better, and start wondering how long you'll need to keep to this framework. The honest answer is: not indefinitely, and certainly not perfectly.

The realistic target is 80% of meals that respect your framework and 20% of freedom: a dinner out, a family meal, a chosen indulgence. Rigidity, on the other hand, has a cost: it impoverishes your diet and keeps meal-related anxiety alive, and stress, as seen above, is a trigger in its own right.

Two points of caution, though. The 20% should be chosen, not endured: a deviation decided in advance digests better than one born of fatigue. And if symptoms genuinely come back, tighten up for a few days rather than starting from zero, an adjustment, not a relapse.

It's this flexibility, as part of a varied and balanced diet and a healthy lifestyle, that makes the approach sustainable over years rather than three weeks.

IBS and stress: your belly, that second brain

Stress isn't the cause of IBS, but it's one of its main triggers: taking it into account is part of the care, with your doctor. Your gut hosts hundreds of millions of neurons, hence the nickname "second brain." When the head struggles, the belly follows. And the other way round.

No need to overhaul everything. A few minutes of slow breathing before meals, regular sleep, a little daily walking. The gut and the head are linked, treat them together.

Conclusion: consistency, not the shock

Let's recap, because this is the essential part. IBS isn't a life sentence, but it isn't an express-cure affair either. What medical guidelines retain: a low-FODMAP diet supervised by a professional, and stress management. The rest is something to discuss with your doctor. What to avoid: aggressive detoxes, stimulant laxatives, enemas, prolonged fasting. And always, in the background, your doctor's follow-up.

Here's what matters to me: giving you honest keys, without scaring you or selling you a dream. We're not here to fill a stomach, but to nourish an organism. At your own pace, always.

Your questions, answered

IBS: what should I eat during a flare?

Favour low-FODMAP, easy-to-digest foods: rice, well-cooked zucchini or carrot, ripe banana, firm tofu, a little olive oil. Temporarily avoid raw vegetables, cruciferous veg, onion, garlic, legumes and dairy. The goal is to calm things down, as part of a varied diet, before gradually widening your plate again.

IBS or a stomach bug: how do I tell them apart?

Gastroenteritis is acute and short-lived (a few days), often with fever, nausea and contagion. IBS is chronic: symptoms return over weeks or months, with no fever and no lesion. When in doubt, or if unusual signs appear, only a doctor can decide.

What should I drink in the morning with IBS?

A large glass of room-temperature water, or a gentle chamomile, lemon balm or fennel tea, is usually well tolerated. Avoid acidic lemon water on an empty stomach, strong coffee and high-fructose fruit juices, which can wake symptoms up.

What else can I do alongside medical follow-up for IBS?

With your doctor: temporarily cutting FODMAP triggers under supervision, taking stress into account and keeping meals simple and regular. These habits never replace your doctor's advice.

Can stress really trigger an IBS flare?

Yes. The gut and brain communicate continuously through the vagus nerve. A spike of stress alters gut motility, increases permeability and can trigger pain and bowel changes. That's why stress management and good sleep are an integral part of an IBS approach.

Are probiotics useful for IBS?

This is a matter for medical advice: not all strains are equal, and the choice of a product is made with a healthcare professional rather than at random.

Should I do a detox when I have IBS?

No aggressive detox: no enemas, no prolonged water fasting, no stimulant laxatives, which most often worsen a sensitive gut. Talk to your doctor for an approach suited to your case.

Scientific references

1. Black, C.J., et al. "Efficacy of a low FODMAP diet in irritable bowel syndrome: systematic review and meta-analysis". Gut / peer-reviewed journal. Meta-analysis of randomized controlled trials (high level of evidence) showing a significant reduction in symptom severity.
2. "Dietary interventions for irritable bowel syndrome: a systematic review and network meta-analysis" (2025). The Lancet Gastroenterology & Hepatology. Network meta-analysis ranking dietary interventions among the most effective in IBS.

In practice

Last updated: November 2026. Article reviewed by Éric Viard, founder of Biovie and ISTOM agronomist, co-author of "Algues au quotidien" (Gallimard, 2024), Best Cookbook in the World, Gourmand Cookbook Awards 2025, and Best Cookbook in France, Académie Nationale de Cuisine 2025.

Disclaimer: the information in this article is provided for general information only and does not constitute medical advice. IBS requires diagnosis and medical follow-up. Consult a qualified healthcare professional before making any change to your diet or supplementation. As part of a varied, balanced diet and a healthy lifestyle.