Ulcerative colitis is a chronic inflammatory bowel disease (IBD) that affects the large intestine (colon) and rectum. It is characterized by continuous mucosal inflammation starting in the rectum and extending proximally to varying degrees. Although often grouped with Crohn’s disease under the umbrella of IBD, ulcerative colitis has distinct clinical, pathological, and treatment features.
What is Ulcerative Colitis?
Ulcerative colitis (UC) is a chronic inflammatory disease affecting only the mucosal layer of the colon. It begins in the rectum and can extend to the entire colon. Unlike Crohn’s disease, UC presents with continuous inflammation without skip lesions and does not affect the small intestine (except in severe pancolitis).
Key Features and Facts
- Affects both men and women equally
- Commonly begins between ages 30–50
- Highest prevalence among Europeans and Jewish communities
- Often shows a relapsing-remitting course
- Associated with extra-intestinal manifestations and increased colon cancer risk after 10 years
Types of Ulcerative Colitis (by extent of inflammation)
| Type | Involvement | Prevalence |
|---|---|---|
| Proctitis | Rectum only | ~30% |
| Distal colitis | Rectum + sigmoid colon | ~30% |
| Left-sided colitis | Rectum to splenic flexure | ~25% |
| Pancolitis (Total colitis) | Entire colon | ~15% |
Causes and Risk Factors
Aetiology
The exact cause of UC is unknown, but several factors contribute:
- Genetic predisposition: HLA-B27, family history
- Autoimmune dysfunction: antibodies against gut epithelial cells
- Environmental triggers: low-fiber diets, infections
- Gut microbiota imbalance
- Smoking: Surprisingly, protective against UC
- NSAIDs and antibiotic use
Pathology of Ulcerative Colitis
Macroscopic:
- Continuous, confluent ulceration
- Hyperemic (reddened), thinned mucosa
- Loss of haustrations (lead-pipe colon)
- No fistulas or transmural lesions
Histological:
- Crypt abscesses
- Crypt distortion and branching
- Mucosal slough and pseudopolyps
- Dense neutrophilic infiltration
- Epithelial dysplasia in long-standing disease
Clinical Features
Intestinal Symptoms:
- Bloody diarrhea with mucus
- Urgency and tenesmus
- Lower abdominal pain, usually left-sided
- Increased stool frequency, especially in proctitis
- Weight loss and fatigue in severe cases
Extra-Intestinal Manifestations (EIMs):
- Eyes: iritis, conjunctivitis, scleritis
- Joints: seronegative arthritis, ankylosing spondylitis
- Skin: erythema nodosum, pyoderma gangrenosum
- Liver: primary sclerosing cholangitis, fatty liver
- Gallstones and blood disorders (rare)
Severe/Fulminant Disease
- 6 bloody stools/day
- Dehydration, fever, weight loss
- Electrolyte imbalance: hypokalemia, hypoalbuminemia
- May progress to toxic megacolon, perforation, or shock
Complications of Ulcerative Colitis
Acute:
- Massive bleeding (acute hemorrhage)
- Severe colitis leading to perforation
- Toxic megacolon
- Hypokalemia, hypoalbuminemia
Chronic:
- Strictures (due to repeated inflammation and fibrosis)
- Dysplasia leading to colorectal carcinoma
- Especially after >10 years of disease
- Higher risk with pancolitis
Diagnosis of Ulcerative Colitis
Blood Tests:
- FBC: Anemia, raised WBC
- ESR, CRP: Inflammatory markers
- Serology: ANCA (positive in UC), ASCA (Crohn’s)
Stool Tests:
- Rule out infections like Clostridium difficile
- Fecal calprotectin
Imaging:
- Abdominal X-ray: Dilated colon, air under diaphragm (in perforation)
- Barium enema: Shortened colon with ‘lead pipe’ appearance
- Radiolabeled scans: For active inflammation
Endoscopy:
- Sigmoidoscopy: Inflammation, bleeding mucosa, granularity
- Colonoscopy with biopsy: Gold standard for diagnosis and monitoring
Treatment: Medical and Surgical Management
Medical Management
1. Dietary and Supportive Care
- High soluble-fiber diet during remission
- Antidiarrheals (avoid in acute flares)
- Avoid NSAIDs
2. Mild to Moderate Disease
- 5-ASA agents (mesalazine, sulfasalazine): Oral and rectal formulations
- Topical steroids (e.g., budesonide) for proctitis
3. Moderate to Severe Disease
- Systemic corticosteroids: Prednisolone
Immunosuppressants:
- Azathioprine, 6-mercaptopurine
- Methotrexate (rarely used)
- Anti-TNF (infliximab, adalimumab)
- Vedolizumab, ustekinumab (advanced cases)
Surgical Management
Indicated for:
- Failure of medical therapy
- Toxic megacolon
- Massive hemorrhage
- Perforation
- Colorectal cancer or high-grade dysplasia
Surgical Options:
- Total Proctocolectomy + End Ileostomy
- Ileoanal Pouch Surgery (J-pouch)
- Preserves continence
- Improves quality of life
Prognosis
- Lifelong disease with remissions and exacerbations
- 10% risk of colorectal cancer at 20 years (higher in pancolitis)
- Normal life expectancy with controlled disease
- Excellent surgical outcomes for refractory or complicated UC
Prevention and Long-term Monitoring
- Regular colonoscopy after 8–10 years for cancer surveillance
- Biopsies of suspicious lesions
- Monitor medication side effects
- Lifestyle adjustments: stress management, exercise, balanced diet
Frequently Asked Questions (FAQs)
Q1. Is ulcerative colitis curable?
A: No, but symptoms can be managed with medications or cured surgically through proctocolectomy.
Q2. What foods should be avoided in UC?
A: During flares, avoid high-fiber, spicy, dairy, and caffeine. In remission, a balanced, anti-inflammatory diet is advised.
Q3. Can UC turn into cancer?
A: Yes, especially after 8–10 years of disease or if pancolitis is present. Regular screenings are crucial.
Q4. Is UC an autoimmune disease?
A: It has autoimmune characteristics but is more accurately described as an immune-mediated inflammatory disease.
Q5. Is UC life-threatening?
A: Rarely. But fulminant colitis and complications like toxic megacolon can be fatal without timely intervention.
Summary: Ulcerative Colitis at a Glance
| Feature | Ulcerative Colitis |
|---|---|
| Inflammation Type | Mucosal, continuous |
| Location | Rectum, colon |
| Complications | Toxic megacolon, cancer, bleeding |
| Extraintestinal | Eyes, joints, skin, liver |
| Treatment | 5-ASA, steroids, biologics |
| Surgery | Total colectomy, J-pouch |
| Monitoring | Regular colonoscopy after 8 years |
