Ulcerative Colitis (UC)
BASICS
Description
- UC is a chronic idiopathic inflammatory bowel disease (IBD) involving the colonic mucosa, usually starting in the rectum and extending proximally in a continuous pattern.
- Presents with bloody and mucoid diarrhea, abdominal pain, rectal urgency, and systemic symptoms.
- Course: Relapsing–remitting with exacerbations and remissions.
- Colonic involvement is universal; systemic involvement (joints, eyes, liver, lungs) may occur.
EPIDEMIOLOGY
| Region | Prevalence |
|---|---|
| North America | 249/100,000 |
| Europe | 505/100,000 |
- Bimodal age distribution: 15–30 years, smaller peak at 50–80 years
- Higher incidence in White and Jewish populations
ETIOLOGY & PATHOPHYSIOLOGY
- Idiopathic: Result of immune dysregulation, genetic susceptibility, and environmental triggers.
- Rectum involved in nearly all adult patients; pancolitis in 20%.
- Genetic syndromes: Turner syndrome, Hermansky-Pudlak syndrome, GSD type 1b.
- Pediatric cases: rectal sparing in up to 33%.
RISK FACTORS
- Family history of IBD
- Enteric infections, NSAID use
- Western diet, obesity
- Lack of breastfeeding in infancy
- Smoking may lower risk of UC (in contrast to Crohn’s)
COMMONLY ASSOCIATED CONDITIONS
| Common | Rare | Very Rare |
|---|---|---|
| Arthritis (large joints) | PSC, pyoderma gangrenosum | Pulmonary disease |
| Aphthous ulcers | Autoimmune hepatitis, cirrhosis | |
| Erythema nodosum | Cholangiocarcinoma | |
| Osteoporosis, fatty liver | Colon cancer | |
| Episcleritis, uveitis | Thromboembolism |
PREGNANCY & PEDIATRIC CONSIDERATIONS
- Conceive during remission (3–6 months stable disease ideal).
- Avoid estrogen-based contraceptives.
- Pancolitis in children is more aggressive; earlier need for colectomy.
- Breastfeeding is protective in pediatric UC.
CLINICAL FEATURES
History
- Gradual onset: small, frequent, bloody or mucoid diarrhea
- Tenesmus, urgency, fecal incontinence, abdominal pain
- Weight loss, fatigue, anorexia
- Extraintestinal: joint pain, eye/skin/liver symptoms
- Relapses in ~50% annually
Physical Exam
- Often normal in mild cases
- Pallor, weight loss, abdominal tenderness
- Severe disease: hypotension, tachycardia, clubbing, edema
DIFFERENTIAL DIAGNOSIS
- Crohn disease
- Infectious colitis (e.g. C. difficile, CMV, Shigella)
- Ischemic colitis, radiation/medication-induced colitis
- IBS, celiac disease
- Pseudomembranous colitis
- Diverticular and diversion colitis
- Graft-vs-host disease
DIAGNOSTIC WORKUP
Initial Labs
| Test | Findings |
|---|---|
| CBC | Anemia, leukocytosis |
| BMP | Electrolyte imbalances (↓K⁺, ↑urea) |
| LFTs | ↓Albumin indicates severity |
| ESR/CRP | Elevated with active inflammation |
| Calprotectin | >782 µg/g in moderate UC; used to monitor |
| Stool tests | Rule out C. difficile, O&P, Shiga toxin |
| STI tests | Especially in MSM patients |
Imaging
- Abdominal X-ray: Check for colonic dilation, assess for toxic megacolon
Endoscopy with Biopsy
- Gold standard
- Continuous colonic involvement, starting at rectum
- Biopsy: Crypt abscesses, inflammatory infiltrates, Paneth cell metaplasia
- Use sigmoidoscopy instead of colonoscopy in severe disease
MONTREAL CLASSIFICATION
| Location | Description |
|---|---|
| E1 | Proctitis |
| E2 | Left-sided (distal to splenic flexure) |
| E3 | Extensive (beyond splenic flexure) |
DISEASE SEVERITY INDEX
| Parameter | Remission | Mild | Moderate-Severe | Fulminant |
|---|---|---|---|---|
| Stools/day | Formed | <4 | 6–10 | >10 |
| Blood in stools | None | Occasional | Frequent | Continuous |
| CRP, ESR | Normal | <30 | >30 | >30 |
| Hemoglobin | Normal | Normal | <75% of normal | Transfusion needed |
| FC µg/g | <150–200 | >150–200 | >150–200 | >150–200 |
TREATMENT STRATEGY
MILD UC (Induction)
| Location | First-line |
|---|---|
| Proctitis | Rectal 5-ASA 1g/day |
| Left-sided | Oral + rectal 5-ASA |
| Extensive | Oral 5-ASA (≥2 g/day) |
| If 5-ASA fails | Add budesonide MMX 9 mg/day → systemic corticosteroids |
MAINTENANCE (Mild UC)
- Proctitis: Rectal 5-ASA
- Left-sided/Extensive: Oral 5-ASA
MODERATE–SEVERE UC
| Induction Options |
|---|
| Oral systemic corticosteroids |
| Budesonide MMX |
| Anti-TNF (adalimumab, infliximab, golimumab) |
| Vedolizumab (integrin blocker) |
| Tofacitinib (JAK inhibitor) |
Reassess within 6 weeks
Maintenance (Moderate-Severe)
- Continue same agent that achieved remission
- Consider thiopurines (azathioprine, 6-MP) after steroid induction
- Taper corticosteroids gradually
- Methotrexate is contraindicated in pregnancy
SURGICAL INDICATIONS
- Failure of medical therapy
- Severe, refractory or fulminant colitis
- Dysplasia or cancer
- Surgery: Total proctocolectomy with ileostomy is curative
ADMISSION & INPATIENT MANAGEMENT
- IV corticosteroids
- Rule out C. difficile and other infections
- Monitor for toxic megacolon, perforation
- Bowel rest (NPO), fluids, TPN if needed
FOLLOW-UP
- Monitor for anemia, malnutrition, depression
- Surveillance colonoscopy: begin 8–10 years after diagnosis, then every 1–2 years
- Assess disease control via calprotectin, CRP
- Address vaccine needs (live vaccines before immunosuppression)
PROGNOSIS
| Factor | Prognosis |
|---|---|
| Age <40 at diagnosis | Poorer prognosis |
| Extensive colitis | ↑ Colectomy risk |
| Severe endoscopic disease | Poorer outcome |
| Elevated CRP, ↓albumin | Poor prognostic markers |
| Fulminant colitis | Mortality ~5% |
- ~75–85% relapse rate
- Up to 20% require colectomy
- Colon cancer is the most serious long-term risk
COMPLICATIONS
- Toxic megacolon → perforation
- Colorectal carcinoma
- Anemia, stricture
- Fulminant colitis
- Extraintestinal: liver disease, osteoporosis
PATIENT EDUCATION
- CCFA: Crohn's & Colitis Foundation
- Smoking cessation (though smoking reduces UC risk, its harms outweigh benefits)
- Medication adherence and surveillance are key to cancer prevention
CODES (ICD-10)
- K51.90 — Ulcerative colitis, unspecified, without complications
- K51.919 — Ulcerative colitis, unspecified, with unspecified complications
- K51.80 — Other ulcerative colitis without complications
CLINICAL PEARLS
- Hallmark: Bloody diarrhea with tenesmus and urgency
- First-line meds: 5-ASA, steroids, biologics (anti-TNF-α)
- Total colectomy is curative
- Colonoscopic surveillance critical after 8 years of disease