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Published on: 1/29/2026

Can untreated IBD cause complications?

Yes, untreated inflammatory bowel disease can lead to progressive intestinal damage with strictures or blockages, fistulas or abscesses, bleeding and iron deficiency anemia, malnutrition and growth delays in children, a higher chance of surgery and colorectal cancer, and complications outside the gut involving the joints, eyes, skin, liver, and bones. There are several factors to consider, and early diagnosis and treatment lower these risks; see below for important details, including red flags that need urgent care and what to discuss with a gastroenterologist to guide your next steps.

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Explanation

Can untreated IBD cause complications?

Short answer: yes. Untreated IBD (Inflammatory Bowel Disease) can lead to a range of complications over time. These complications don't happen to everyone, and many are preventable with timely care. Understanding the risks can help you make informed decisions and know when to seek medical advice—without unnecessary fear.

IBD is a chronic condition that includes Crohn's disease and ulcerative colitis. In both, the immune system causes ongoing inflammation in the digestive tract. When that inflammation is not controlled, it can gradually damage the gut and sometimes affect other parts of the body.

Below is a clear, practical look at what can happen if IBD is left untreated, why treatment matters, and what you can do next.


Why untreated IBD can become a problem

Inflammation is your body's natural response to injury or infection. In IBD, that response doesn't turn off. Over months or years, persistent inflammation can:

  • Injure the lining of the bowel
  • Interfere with digestion and nutrient absorption
  • Spread beyond the gut to joints, skin, eyes, or liver

Medical guidelines from major gastroenterology organizations consistently show that early diagnosis and treatment reduce complications and improve long-term quality of life.


Intestinal complications of untreated IBD

1. Ongoing bowel damage

Chronic inflammation can slowly change the structure of the intestines.

  • In Crohn's disease, inflammation can extend through the full thickness of the bowel wall
  • In ulcerative colitis, damage affects the inner lining of the colon

Over time, this damage may become harder to reverse.

2. Narrowing of the bowel (strictures)

Repeated inflammation and healing can lead to scar tissue.

  • Scar tissue can narrow the intestine
  • This may cause cramping, bloating, constipation, or bowel blockage
  • Severe blockages may require urgent treatment or surgery

3. Fistulas and abscesses (mainly Crohn's disease)

Untreated inflammation can create abnormal tunnels (fistulas) between:

  • Two parts of the intestine
  • The intestine and skin
  • The intestine and bladder or other organs

Fistulas can lead to infection and pain. Abscesses (pockets of infection) may also develop and often require medical treatment.

4. Bleeding and anemia

Inflamed bowel tissue can bleed.

  • Small, ongoing blood loss may not be obvious
  • Over time, this can cause iron-deficiency anemia

Symptoms may include fatigue, shortness of breath, dizziness, or pale skin.


Nutritional and growth-related complications

5. Malnutrition

IBD can interfere with how your body absorbs nutrients.

  • Reduced appetite due to pain or nausea
  • Poor absorption of vitamins and minerals
  • Increased nutritional needs during inflammation

Common deficiencies include iron, vitamin B12, vitamin D, calcium, and protein.

6. Delayed growth in children and teens

In children and adolescents, untreated IBD can:

  • Slow height and weight gain
  • Delay puberty

This is one reason early diagnosis and treatment are especially important in younger people.


Increased risk of surgery

When IBD is not controlled:

  • Damage can build up over time
  • Medications may become less effective later
  • Surgery may become more likely

While surgery can be life-saving and beneficial for some, many people prefer to avoid it when possible. Treating IBD early often reduces the need for surgical intervention.


Risk of colorectal cancer

Long-standing, untreated inflammation of the colon increases the risk of colorectal cancer, particularly in:

  • Ulcerative colitis affecting much of the colon
  • Crohn's disease involving the colon
  • Disease lasting longer than 8–10 years

Regular monitoring and controlling inflammation are key strategies for lowering this risk.


Complications outside the digestive tract

IBD is a whole-body condition, not just a bowel disease. Untreated IBD can affect other organs.

7. Joint, skin, and eye problems

Possible complications include:

  • Joint pain or arthritis
  • Painful skin rashes or sores
  • Eye inflammation causing redness, pain, or blurred vision

These symptoms often improve when IBD is well controlled.

8. Liver and bile duct disease

Some people with IBD develop liver-related conditions, such as inflammation of the bile ducts. While uncommon, these conditions require medical monitoring.

9. Bone thinning (osteoporosis)

Chronic inflammation, poor nutrient absorption, and steroid use can weaken bones, increasing fracture risk over time.


Emotional and mental health impact

Living with untreated IBD can affect emotional well-being.

  • Ongoing symptoms may limit work, school, or social activities
  • Uncertainty and physical discomfort can increase stress
  • Anxiety or depression may develop, especially when symptoms feel out of control

Addressing IBD often improves both physical and mental quality of life.


IBD vs. IBS: why the difference matters

IBD is sometimes confused with IBS (Irritable Bowel Syndrome), but they are not the same.

  • IBD causes visible inflammation and tissue damage
  • IBS affects bowel function but does not cause inflammation or permanent damage

If you're experiencing digestive symptoms and want to understand what might be causing them, Ubie's free AI-powered Irritable Bowel Syndrome (IBS) symptom checker can help you explore whether your symptoms align with IBS and guide your next steps toward getting proper care.


Can complications be prevented?

In many cases, yes.

Modern IBD care focuses on:

  • Reducing inflammation early
  • Preventing long-term bowel damage
  • Monitoring for complications
  • Adjusting treatment as the disease changes

Treatment plans may include medications, nutrition support, lifestyle adjustments, and regular follow-up. Many people with IBD live full, active lives when their condition is properly managed.


When to speak to a doctor

You should speak to a doctor—preferably a gastroenterologist—if you have:

  • Ongoing diarrhea lasting more than a few weeks
  • Blood in your stool
  • Unexplained weight loss
  • Persistent abdominal pain
  • Fatigue combined with bowel symptoms

Seek urgent medical care for severe pain, heavy bleeding, fever, or signs of bowel blockage, as these can be life-threatening if not treated promptly.


The bottom line

Untreated IBD can cause serious complications, but these outcomes are not inevitable. The greatest risks come from ongoing, uncontrolled inflammation over time. Early evaluation, accurate diagnosis, and appropriate treatment significantly lower the chance of long-term damage.

If something doesn't feel right, trust your instincts, gather information, and speak to a doctor about your symptoms—especially if they could be serious. Taking action sooner rather than later can make a meaningful difference in your long-term health.

(References)

  • * Mane S, Palabindala V, Sunkara T, Gutta N, Guda NM. Complications of inflammatory bowel disease: a narrative review. World J Gastrointest Pharmacol Ther. 2021 Dec 26;12(6):109-122. doi: 10.4292/wjgpt.v12.i6.109. PMID: 35002011; PMCID: PMC8725458.

  • * Feagan BG, Sandborn WJ. Long-term complications of inflammatory bowel disease. Curr Opin Gastroenterol. 2015 Jul;31(4):276-83. doi: 10.1097/MOG.0000000000000185. PMID: 26046406.

  • * Rosen MJ, Dhawan A, D'Amico MA, Zvibel I. The Natural History of Inflammatory Bowel Disease. Clin Colon Rectal Surg. 2018 Mar;31(2):63-71. doi: 10.1055/s-0037-1607421. PMID: 29509497; PMCID: PMC5836262.

  • * Ghorbani P, Arefayen M, Maleki I. Complications of ulcerative colitis: A narrative review. J Coloproctol (Rio J). 2021 Dec;41(4):460-466. doi: 10.1016/j.jcol.2021.05.006. Epub 2021 Aug 11. PMID: 34365313; PMCID: PMC8722421.

  • * Alhagamhmad MH, Hassanain M. Complications of Crohn's Disease. Surg Clin North Am. 2017 Oct;97(5):1013-1024. doi: 10.1016/j.suc.2017.06.002. PMID: 29015949.

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