What are the causes of ileitis (inflammation of the ileum)?

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Last updated: March 7, 2025View editorial policy

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From the Guidelines

Ileitis is primarily caused by Crohn's disease, a type of inflammatory bowel disease that can affect any part of the digestive tract, including the ileum, as supported by the most recent guidelines 1. The causes of ileitis can be multifactorial, including:

  • Inflammatory bowel disease, specifically Crohn's disease, which is characterized by transmural inflammation that can occur in the entire gastrointestinal tract, including the terminal ileum and colon 1
  • Infections such as Yersinia enterocolitica, Salmonella, Campylobacter, and tuberculosis
  • Medication-induced ileitis, which can occur from non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or naproxen
  • Ischemic ileitis, resulting from reduced blood flow to the ileum, often due to atherosclerosis, blood clots, or vascular compression
  • Radiation therapy to the abdomen or pelvis, which can cause radiation-induced ileitis
  • Certain systemic conditions like vasculitis, Behçet's disease, and sarcoidosis, which may also lead to ileitis The diagnosis of ileitis typically involves a combination of clinical evaluation, laboratory tests, imaging studies, and sometimes endoscopy with biopsy, as outlined in the guidelines for the management of inflammatory bowel disease in the emergency setting 1. Treatment of ileitis depends on the underlying cause and may include:
  • Antibiotics for infections
  • Anti-inflammatory medications for Crohn's disease, such as mesalamine, corticosteroids, immunomodulators like azathioprine, or biologics like infliximab, as recommended in the guidelines 1
  • Discontinuation of offending medications
  • Surgery in severe cases, although the number of cases performed seems to have decreased in recent years, likely due to the introduction of anti-TNF therapy and improved multidisciplinary IBD management 1

From the Research

Causes of Ileitis

The causes of ileitis, or inflammation of the ileum, are varied and can be attributed to several factors, including:

  • Infectious diseases, such as bacterial, viral, or parasitic infections 2, 3, 4
  • Inflammatory bowel diseases, such as Crohn's disease and ulcerative colitis 2, 5, 4
  • Spondyloarthropathies, a group of diseases that cause inflammation in the joints and other parts of the body 2, 4
  • Vasculitides, a group of diseases that cause inflammation in the blood vessels 2, 4
  • Ischemia, a condition that occurs when there is a lack of blood flow to the ileum 2, 4
  • Neoplasms, or tumors, that can cause inflammation in the ileum 2, 4
  • Medication-induced ileitis, such as that caused by non-steroidal anti-inflammatory drugs (NSAIDs) 2, 4
  • Eosinophilic enteritis, a condition that causes inflammation in the small intestine 2, 4
  • Other conditions, such as sarcoidosis and amyloidosis 4

Role of Infection in Ileitis

Infection is thought to play a role in the development of ileitis, with various pathogens implicated in the disease, including:

  • Mycobacterium paratuberculosis 3
  • Escherichia coli 3
  • Listeria monocytogenes 3
  • Chlamydia 3
  • Viruses, such as measles, mumps, rubella, Epstein-Barr virus, and cytomegalovirus 3

Importance of Diagnosis

Diagnosing the underlying cause of ileitis is crucial for effective treatment and management of the condition 2, 4. A detailed history and physical examination, laboratory testing, and ileocolonoscopy and/or radiologic data are necessary to determine the specific etiology of ileitis 2.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Ileitis: when it is not Crohn's disease.

Current gastroenterology reports, 2010

Research

Facing Terminal Ileitis: Going Beyond Crohn's Disease.

Gastroenterology research, 2016

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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