Inflammatory Bowel Disease (IBD)
Inflammatory bowel disease (IBD) is a chronic immune-mediated condition that causes inflammation of the digestive tract. The two main types are Crohn's disease and ulcerative colitis.
Quick Facts
- Type: Chronic immune-mediated GI disease
- Main forms: Crohn's, ulcerative colitis
- Typical onset: 15–35 years old
- Treatment: Anti-inflammatory and immune therapies
Overview
IBD refers to chronic inflammation of the digestive tract driven by an abnormal immune response. It is different from irritable bowel syndrome (IBS), which causes symptoms without inflammation or tissue damage.
- Crohn's disease — can affect any part of the GI tract from mouth to anus; inflammation extends through the full thickness of the bowel wall.
- Ulcerative colitis — limited to the colon and rectum; inflammation involves only the inner lining.
Symptoms
- Persistent or bloody diarrhea
- Abdominal pain and cramping
- Unintended weight loss
- Fatigue
- Fever during flares
- Urgency to have bowel movements
- Mucus or pus in stool
- Reduced appetite
Outside the gut
- Joint pain
- Eye inflammation
- Skin rashes
- Liver inflammation (especially primary sclerosing cholangitis with UC)
Causes
The exact cause is unknown, but IBD develops from a combination of:
- Genetic susceptibility
- An abnormal immune response, possibly triggered by gut bacteria
- Environmental factors (smoking, diet, NSAID use, antibiotics, gastroenteritis history)
Diagnosis
- Blood tests for inflammation and anemia
- Stool tests (calprotectin, lactoferrin, infection screening)
- Colonoscopy with biopsies (gold standard)
- Upper endoscopy if upper GI involvement suspected
- Cross-sectional imaging (CT or MR enterography)
Treatment
Medications
- Aminosalicylates (5-ASA) — first-line in mild ulcerative colitis
- Corticosteroids — for flares, not for long-term use
- Immunomodulators — azathioprine, methotrexate
- Biologic therapies — anti-TNF (infliximab, adalimumab), anti-integrin, anti-IL-23, anti-IL-12/23
- Small-molecule therapies — JAK inhibitors, S1P modulators
Lifestyle
- Quit smoking (worsens Crohn's)
- Nutritional support during flares
- Avoid foods that personally trigger symptoms
- Manage stress
Surgery
- Crohn's — to remove diseased bowel segments or treat strictures/fistulas
- Ulcerative colitis — colectomy can be curative (since UC is limited to the colon)
When to See a Doctor
See a gastroenterologist for persistent diarrhea, blood in stool, unexplained weight loss, or recurrent abdominal pain. Seek urgent care for severe abdominal pain, distension, high fever, or signs of dehydration.
Frequently Asked Questions
No. IBS (irritable bowel syndrome) is a functional disorder that causes symptoms without visible inflammation. IBD causes actual inflammation and tissue damage, can be seen on colonoscopy, and increases long-term complications including cancer risk.
No specific diet has been shown to cure IBD. Some patients identify personal trigger foods; supervised nutritional therapy can help during flares. Diet is supportive, not curative.
Biologics modulate parts of the immune system and slightly increase infection risk. Routine screening and vaccination help reduce this risk, and benefits typically outweigh harms in moderate-severe IBD.
Long-standing IBD, especially ulcerative colitis affecting most of the colon, increases colorectal cancer risk. Regular surveillance colonoscopies are recommended.
References
- American Gastroenterological Association. IBD Practice Guidelines.
- Crohn's & Colitis Foundation. About Crohn's & Colitis.