When you're in a flare, you don't need theory. You need someone to tell you what to do right now, today, to get through the next few hours and the ones after that. I know because I've been there. Not as a practitioner reading about it in a textbook, but flat on my back, dehydrated, watching the clock and dreading every meal.
I was diagnosed with Crohn's disease in 2015. I recovered without medication and I've been symptom-free for more than eight years now. But I haven't forgotten what a flare feels like. The urgency that hits without warning. The pain that makes you curl up on the bathroom floor. The exhaustion from broken sleep, night after night. I remember all of it, and so does every client I work with.
This article is the practical guide I wish I'd had. Not vague reassurances, but specific things you can do to support your body while it's under attack.
What's actually happening during a flare
Understanding what's going on inside your colon makes it easier to understand why certain things help and others make it worse. During a flare, your colon wall is actively inflamed. The lining that normally absorbs water and forms solid stools is swollen, irritated, and in some areas ulcerated. Those ulcerations bleed, which is why you see blood in the toilet.
Because the inflamed colon can't absorb water properly, everything moves through too fast. That's where the diarrhoea comes from — sometimes up to 20 or 30 times a day. It's often worse at night and in the early morning, which means your sleep gets destroyed at exactly the moment your body needs rest the most.
Eating becomes its own problem. Food entering the digestive system triggers contractions in the colon (a normal reflex called the gastrocolic reflex), but when the colon is inflamed, those contractions cause painful cramping. So you eat, and within minutes you're in agony. Many people stop eating properly during a flare, which leads to weight loss, nutrient deficiencies, and even more fatigue.
Fever and dehydration often come with it. Your body is running an inflammatory response that takes enormous energy, and you're losing fluids faster than you can replace them. It's a brutal cycle, and breaking it requires working on several things at once.
What to eat during a flare (and what to avoid)
Your inflamed colon cannot handle the foods it normally processes. Raw vegetables, high-fibre grains, nuts, seeds, spicy food, alcohol, caffeine — all of these irritate an already damaged gut lining. During a flare, you need to eat foods that are easy to digest, gentle on the colon, and still provide the nutrients your body desperately needs.
What works well for most people during an active flare:
- Homemade chicken bone broth — rich in glycine and collagen, easy to digest, and hydrating. More on this below.
- Soft steamed vegetables — courgette, carrots, and sweet potato, cooked until very soft. No raw vegetables during a flare.
- Soft white rice — low residue, easy on the colon, provides energy without irritation.
- Steamed fish — gentle protein that doesn't tax your digestive system.
- Simple soups — blended vegetable soups with bone broth as a base.
If things are really bad — constant urgency, severe cramping, unable to keep much down — stick to homemade soups and bone broth only. Small amounts, often. Don't force large meals. Your colon is telling you it can't cope, and fighting that makes everything worse.
As the flare settles, you can gradually reintroduce more foods. But during the acute phase, simplicity is your friend.
Targeted probiotics: strain specificity matters
Not all probiotics are the same, and picking up a random supplement from the health food shop is unlikely to help with a UC flare. What research consistently shows is that strain specificity matters. The bacteria that help with IBS bloating are not the same ones that reduce colonic inflammation.
Two formulations stand out in the research for ulcerative colitis specifically:
VSL#3 is one of the most studied multi-strain probiotic formulations for UC. It contains eight bacterial strains at very high concentrations. A study from the University of Alberta found it effective for maintaining remission in UC, and umbrella meta-analyses of probiotic research consistently rank it among the strongest evidence for ulcerative colitis.
E. coli Nissle 1917 (sold as Mutaflor in Europe) is a single-strain probiotic that has been well-researched specifically for UC maintenance. Studies have shown it to be comparable to mesalazine (a standard UC medication) for preventing relapse. That's a significant finding — a probiotic performing at the same level as a pharmaceutical drug.
What I tell clients: during a flare, targeted probiotics are one of the first things to consider alongside dietary changes. But "targeted" is the key word. You need the right strains, at the right dose, for your specific condition.
L-glutamine for gut lining repair
Your gut lining is made up of cells called enterocytes, and their preferred fuel source is an amino acid called L-glutamine. When your colon is inflamed and the lining is damaged, those cells need more glutamine than usual to repair themselves.
A meta-analysis covering 352 participants found that L-glutamine supplementation at doses above 30 grams per day was effective for supporting gut lining repair. That's a meaningful dose — much higher than what most supplements contain. If you're considering glutamine during a flare, the research suggests you need adequate amounts to see a real effect. This is worth discussing with a practitioner who understands dosing.
Bone broth and collagen: supporting your tight junctions
Your gut lining isn't just a wall — it's a selective barrier. The cells are held together by structures called tight junctions, which decide what gets through into your bloodstream and what stays in the gut. When those junctions are compromised (what's commonly called leaky gut), partially digested food particles and bacterial fragments cross into the bloodstream, triggering immune reactions that drive more inflammation.
Bone broth is rich in glycine, an amino acid that supports the integrity of those tight junctions. One study found a 93% improvement in gut barrier function with glycine supplementation. Collagen, which breaks down into glycine and other amino acids during cooking, is why homemade bone broth (simmered for 12 to 24 hours with bones, not the powdered kind from a packet) is so consistently recommended by practitioners who work with gut conditions.
During a flare, bone broth does double duty: it's one of the easiest things to digest while also delivering the raw materials your gut lining needs to repair itself.
Breaking the stress-gut cycle
Stress doesn't just feel bad — it directly damages your gut. Cortisol, the hormone your body produces under stress, weakens the gut lining and shifts your gut bacteria toward less favourable populations. A flare causes stress (the pain, the disruption to your life, the anxiety about whether it will get worse), and that stress makes the flare worse. It's a vicious circle, and breaking it matters.
I'm not going to tell you to "just relax" — anyone who's been through a flare knows that's useless advice. But I will say that even small things make a difference. Ten minutes of slow breathing before bed. A short walk outside if you're able. Reducing work commitments where you can. Anything that brings your cortisol down, even slightly, gives your gut a better chance to recover.
Sleep is connected to this as well. Your gut contains roughly 400 times more melatonin than your brain, and melatonin plays a direct role in gut repair and reducing intestinal inflammation. When a flare wrecks your sleep (and it will — the nighttime urgency makes sure of that), you lose the very hormone your gut needs to heal. If you can manage even slightly better sleep — a dark room, no screens before bed, magnesium glycinate in the evening — it's worth doing.
Omega-3 fatty acids: calming the inflammatory fire
Most people with inflammatory bowel disease have an imbalance between omega-6 and omega-3 fatty acids. Omega-6 (found in seed oils, processed food, and conventionally raised meat) drives inflammation. Omega-3 (found in oily fish, flaxseed, and algae) does the opposite. It reduces the activity of NF-kB, one of the main inflammatory pathways in your body, and supports beneficial bacteria like Akkermansia in your gut.
During a flare, supplementing with a good-quality fish oil or eating oily fish (salmon, mackerel, sardines) several times a week can help rebalance that ratio. It won't stop a flare on its own, but it's one more thing tipping the scales away from inflammation and toward recovery.
When to see your doctor
Everything in this article is meant to support your recovery, not replace medical care. If you're experiencing heavy bleeding, a fever that won't come down, severe dehydration, or weight loss you can't stop, you need to see your doctor or gastroenterologist. A bad flare can lead to complications that require medical intervention, and there's nothing contradictory about combining natural approaches with medical oversight when you need it.
What I always say to clients: use everything available to you. The dietary changes, the targeted supplements, the lifestyle adjustments — and keep your medical team informed about what you're doing. The goal is to get better, not to prove a point.
Getting through a flare is hard. Getting to the root cause is what changes things.
A flare is your body telling you something is wrong, and while managing the acute symptoms matters, what matters more in the long run is understanding why the flare happened in the first place. In our practice at Eerste hulp bij Darmklachten, that's what we focus on: not just getting through the crisis, but building a personalised programme that addresses the underlying factors driving your condition.
We work with people across Europe through online consultations, and the first conversation is always free, with no obligation and no sales pitch. If you're dealing with recurrent flares and you want to understand what's going on underneath them, that's what we're here for.
References
- Shen, J. et al. (2017) — Effect of probiotics on inducing remission and maintaining therapy in ulcerative colitis: a meta-analysis. Umbrella review of probiotic strain specificity.
- Jonkers, D. et al. — VSL#3 probiotic mixture for maintaining remission in ulcerative colitis. University of Alberta study.
- Kruis, W. et al. (2004) — Maintaining remission of ulcerative colitis with the probiotic E. coli Nissle 1917 is as effective as standard mesalazine. Gut, 53(11), 1617-1623.
- Peng, L. et al. — Meta-analysis: L-glutamine supplementation and gut barrier function. 352 participants, doses >30g/day effective.
- Li, Y. et al. — Glycine supplementation and intestinal barrier function: systematic review.
- Konturek, P.C. et al. (2011) — Stress and the gut: pathophysiology, clinical consequences, diagnostic approach and treatment options. Journal of Physiology and Pharmacology, 62(6), 591-599.
- Sommansson, A. et al. — Melatonin and its role in the gastrointestinal tract: 400x higher concentration in the gut compared to the pineal gland.
- Calder, P.C. (2010) — Omega-3 fatty acids and inflammatory processes. Nutrients, 2(3), 355-374.