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Published on: 3/12/2026

Still Flaring on Skyrizi? Why Your Crohn’s is Resisting and New Medical Next Steps

If you are still flaring on Skyrizi, there are several factors to consider; see below to understand more.

Likely causes include primary non-response, secondary loss of response from low drug levels or antibodies, mechanical complications, or a different condition, and next steps usually include targeted blood and stool tests, optimizing Skyrizi or brief steroids, switching to another biologic or a JAK inhibitor, and addressing complications, with urgent red flags and decision guidance outlined below.

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Explanation

Still Flaring on Skyrizi? Why Your Crohn's Is Resisting and New Medical Next Steps

If you're experiencing a Crohn's flare while on Skyrizi, you're not alone — and you're not failing treatment. Skyrizi (risankizumab) is an advanced biologic medication approved for moderate to severe Crohn's disease. It works by targeting interleukin‑23 (IL‑23), a key driver of inflammation in the gut. For many people, it reduces symptoms and helps achieve remission.

But no Crohn's treatment works for everyone.

If your symptoms are continuing — or coming back — here's what could be happening and what medical next steps may look like.


First: What Counts as a Crohn's Flare?

A flare means active inflammation is happening again. Symptoms can include:

  • Persistent diarrhea
  • Abdominal pain or cramping
  • Blood in stool
  • Urgency
  • Fatigue
  • Weight loss
  • Fever
  • Joint pain

Sometimes symptoms feel like a flare but are caused by something else — like infection, irritable bowel syndrome (IBS), bile acid malabsorption, or small intestinal bacterial overgrowth (SIBO). That's why testing matters.


Why Am I Having a Crohn's Flare While on Skyrizi?

There are several medically recognized reasons why Skyrizi may not be fully controlling your disease.

1. Primary Non-Response

About 20–40% of patients starting any biologic therapy may not respond adequately. This is called primary non-response.

Possible reasons include:

  • Your immune system is driven by inflammatory pathways beyond IL‑23
  • The medication does not sufficiently suppress your particular disease pattern
  • Severe or longstanding disease that's harder to control

If you never achieved remission after starting Skyrizi, your doctor may consider this possibility.


2. Secondary Loss of Response

Some people initially improve — then symptoms gradually return. This is called secondary loss of response.

It can happen because:

  • Inflammation adapts and finds alternate pathways
  • Drug levels in your blood are too low
  • Your body develops antibodies that reduce effectiveness (less common with Skyrizi than older biologics, but still possible)

Doctors may check drug levels and inflammatory markers before making changes.


3. Inadequate Drug Levels

Biologic medications must reach therapeutic levels in your bloodstream. If levels are too low, the drug cannot fully control inflammation.

Reasons levels may be low:

  • Faster metabolism
  • Higher body weight
  • Severe inflammation increasing drug clearance
  • Dosing schedule not optimized

Sometimes adjusting dosing frequency or timing can help.


4. Structural Damage or Complications

If Crohn's disease has caused complications, medication alone may not fully relieve symptoms.

Possible complications include:

  • Strictures (narrowed bowel segments)
  • Fistulas
  • Abscesses
  • Scar tissue

In these cases, inflammation may not be the only problem — mechanical issues may require additional treatments, including procedures or surgery.


5. An Overlapping Condition

Not every symptom during treatment is active Crohn's inflammation.

Other conditions that can mimic a flare:

  • Irritable bowel syndrome (IBS)
  • Infection (including C. diff)
  • Viral gastroenteritis
  • Bile acid diarrhea
  • Small intestinal bacterial overgrowth
  • Medication side effects

Your doctor may order stool tests, blood tests, imaging, or endoscopy to clarify what's happening.


What Tests Should Be Done?

If you're experiencing a Crohn's flare while on Skyrizi, evaluation is important. Your care team may recommend:

  • Blood tests
    • C-reactive protein (CRP)
    • Complete blood count
    • Electrolytes
  • Stool tests
    • Fecal calprotectin (measures gut inflammation)
    • Infection screening
  • Imaging
    • MRI enterography
    • CT scan
  • Colonoscopy
    • Direct visualization of inflammation

These tests help determine whether inflammation is active — and guide next steps.


New Medical Next Steps If Skyrizi Isn't Working

Treatment decisions depend on test results and disease severity.

1. Optimize Skyrizi

Before switching therapies, your doctor may:

  • Confirm dosing schedule
  • Check drug levels
  • Adjust timing of injections
  • Evaluate adherence

Sometimes small adjustments improve outcomes.


2. Add Short-Term Steroids

If inflammation is significant, a short course of corticosteroids may help calm an acute flare while a long-term strategy is decided.

Steroids are not a long-term solution but can stabilize symptoms.


3. Switch to Another Biologic or Advanced Therapy

If Skyrizi is not effective, other FDA-approved options include:

  • Anti-TNF medications (like infliximab or adalimumab)
  • Anti-integrin therapy (vedolizumab)
  • Other IL-23 inhibitors
  • JAK inhibitors (such as upadacitinib, in appropriate patients)

Each medication works differently. Your doctor will consider:

  • Your disease severity
  • Location of inflammation
  • Previous medications
  • Risk profile
  • Other health conditions

4. Combination Therapy

In some cases, combining therapies improves outcomes. This must be done carefully due to infection risks and requires specialist supervision.


5. Address Complications

If strictures, fistulas, or abscesses are present:

  • Antibiotics may be prescribed
  • Drainage procedures may be needed
  • Surgery may be recommended

Surgery is not a failure. For many patients, it improves quality of life and reduces long-term complications.


Lifestyle Factors That Matter

Medication is critical — but other factors also influence inflammation.

Consider reviewing:

  • Smoking status (smoking worsens Crohn's outcomes)
  • Nutrition (malnutrition can worsen symptoms)
  • Stress management
  • Sleep quality
  • Medication adherence

Diet changes alone rarely replace biologics in moderate-to-severe Crohn's disease, but nutrition optimization supports healing.


When to Seek Urgent Medical Care

Some symptoms require immediate evaluation. Contact a doctor urgently or seek emergency care if you experience:

  • Severe abdominal pain
  • Persistent vomiting
  • High fever
  • Black or bloody stools
  • Signs of dehydration
  • Rapid heart rate
  • Severe weakness

Crohn's disease can cause serious complications. Prompt care can prevent long-term damage.

Always speak to a doctor immediately about anything that could be life threatening or serious.


Could It Really Be Active Crohn's?

Sometimes symptoms feel like inflammation but aren't.

If you're unsure whether what you're experiencing reflects active disease, a free AI-powered Crohn's Disease symptom checker can help you understand your symptoms before your next doctor's appointment and give you clarity on whether what you're feeling may be related to active inflammation or something else entirely.

This is not a substitute for medical care — but it can help you organize your concerns.


The Bigger Picture: Crohn's Treatment Is Often a Journey

Crohn's disease is complex. Even with modern biologics like Skyrizi, many patients need:

  • Dose adjustments
  • Medication changes
  • Combination approaches
  • Monitoring and reassessment

Having a Crohn's flare while on Skyrizi does not mean your condition is untreatable. It means your care plan may need refinement.

Medical research continues to expand treatment options. IL‑23 inhibitors like Skyrizi are part of a growing toolbox — not the final stop if symptoms persist.


What You Should Do Next

If you're flaring:

  1. Document your symptoms clearly.
  2. Contact your gastroenterologist promptly.
  3. Ask about inflammatory testing.
  4. Discuss whether optimization or switching therapy is appropriate.
  5. Review possible complications.
  6. Address lifestyle factors.

Avoid stopping biologic therapy without medical supervision.


Final Thoughts

Experiencing a Crohn's flare while on Skyrizi can feel discouraging. But it is a recognized clinical situation with clear next steps. The key is structured evaluation — not guesswork.

Most importantly:

  • Do not ignore worsening symptoms.
  • Do not self-adjust medication.
  • Speak to a doctor about any serious or life‑threatening symptoms immediately.

With careful reassessment and the right adjustments, many patients regain control of their disease and move back toward remission.

(References)

  • * Ferrante M, D'Angelo F, Sandborn WJ. Risankizumab for the Treatment of Crohn's Disease. *Gastroenterol Hepatol*. 2023 Mar;46(3):213-222. doi: 10.1016/j.jhepr.2023.01.006. Epub 2023 Jan 25. PMID: 36706972.

  • * Ungaro R, Agrawal M, Dassopoulos T, et al. Mechanisms and management of nonresponse to biologic therapies in inflammatory bowel disease. *Nat Rev Gastroenterol Hepatol*. 2023 Jul;20(7):445-463. doi: 10.1038/s41575-023-00770-y. Epub 2023 Apr 28. PMID: 37117180.

  • * Colombel JF, Dulai PS, D'Haens G, et al. Mechanisms of Resistance to Anti-IL-23 Agents in Inflammatory Bowel Disease. *J Crohns Colitis*. 2022 Sep 1;16(Supplement_2):S160-S170. doi: 10.1093/ecco-jcc/jjac016. PMID: 35147414.

  • * Hanauer SB. Next-Generation Biologics for the Treatment of Crohn's Disease. *Gastroenterol Clin North Am*. 2022 Jun;51(2):341-356. doi: 10.1016/j.gtc.2022.02.001. Epub 2022 Apr 14. PMID: 35641066.

  • * Goyal A, Khan H, Khurana S, Sandhu Y, Kichloo A. Emerging Therapies in Crohn's Disease. *Gastroenterol Res*. 2022 Dec;15(6):369-376. doi: 10.14740/gr1570. Epub 2022 Dec 19. PMID: 36568114.

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