skip to main content
usmle step 2 ck

Inflammatory Bowel Disease — Ulcerative Colitis

Continuous mucosal inflammatory bowel disease beginning in the rectum and extending proximally through the colon, causing bloody diarrhea and urgency

Review date
reviewed 2026-05-04
Reading time
9 min read
Author
Dr Kola Tytler MBBS CertHE MBA MSt MRCGP
Gastroenterology & Hepatologycommonlong-term-condition
On this page
Condition details
Gastroenterology & Hepatology
common
9 min read
reviewed 2026-05-04
practice step 2 ck questions →

About This Page

This is a clinician-written, evidence-based summary aligned to the USMLE Step 2 CK Content Outline. It is intended for medical students preparing for USMLE Step 2 CK. Management reflects current ACC/AHA, USPSTF, and APA guidelines. Always cross-reference with UpToDate, institutional protocols, and clinical judgment.

Key points

  • UC = continuous mucosal inflammation starting in the rectum and extending proximally
  • Classic symptoms: bloody diarrhea, urgency, tenesmus, crampy lower abdominal pain
  • Diagnosis: colonoscopy with biopsy after excluding infection; avoid full colonoscopy in toxic megacolon
  • Mild-moderate disease: 5-ASA; moderate-severe flares: corticosteroids for induction
  • Colectomy is curative for colonic disease and indicated for dysplasia/cancer or refractory complications

Overview

Ulcerative colitis is chronic IBD limited to the colon. Inflammation is continuous, starts in the rectum, and is usually mucosal/submucosal rather than transmural. Extent ranges from proctitis to pancolitis.

Epidemiology

UC often begins between ages 15 and 35. Risk increases with family history and Ashkenazi Jewish ancestry. It is associated with primary sclerosing cholangitis and colorectal cancer risk after years of colitis.

Clinical Features

Symptoms
Chronic diarrhea with abdominal pain
Weight loss, fatigue, anorexia
Extraintestinal manifestations: arthritis, erythema nodosum, episcleritis, uveitis
Fever, obstruction, severe bleeding, abscess, or toxic megacolon features
Signs
Abdominal tenderness
Pallor or weight loss
Perianal disease favors Crohn; rectal bleeding/tenesmus favors UC
Peritonitis, sepsis, or marked distension

Investigations

First-line
CBC, CMP, CRP/ESRAnemia, leukocytosis, hypoalbuminemia, inflammatory burden
Stool studies including C difficileExclude infection before immunosuppression
Fecal calprotectinSupports intestinal inflammation and helps distinguish IBD from IBS
Second-line
Colonoscopy with biopsyDefines extent, severity, and histology
CT or MR enterographySmall bowel disease, strictures, fistulas, abscesses; especially Crohn
Specialist
Pelvic MRIComplex perianal Crohn disease
Flexible sigmoidoscopyAcute severe colitis when full colonoscopy is unsafe

Management

ACG Clinical Guideline: Ulcerative Colitis in Adults
1
Induction
  • Budesonide for mild ileocecal Crohn; 5-ASA for mild UC
  • Systemic corticosteroids for moderate-severe flares
  • Hospitalize severe colitis, obstruction, abscess, or systemic toxicity
2
Maintenance
  • Steroids are never maintenance therapy
  • Use immunomodulators, biologics, or targeted small molecules according to severity
  • Vaccinate and screen for TB/HBV before biologics
3
Surgery/surveillance
  • Crohn surgery treats complications but is not curative
  • Colectomy cures UC colitis and is indicated for dysplasia/cancer or toxic megacolon
  • Colon cancer surveillance after long-standing colitis

Complications

  • Crohn: Fistulas, abscesses, strictures, SBO, malabsorption.
  • UC: Toxic megacolon, severe bleeding, PSC, colorectal cancer.
  • Extraintestinal disease: Arthritis, uveitis, erythema nodosum, pyoderma gangrenosum.
  • Medication complications: Infection and malignancy risks with immunosuppression.
USMLE Step 2 CK Exam Tips
  • 1Crohn = skip lesions + transmural inflammation + fistulas; UC = continuous mucosal disease starting at rectum
  • 2Perianal fistula strongly favors Crohn
  • 3UC toxic megacolon: fever, tachycardia, abdominal distension, colon >6 cm
  • 4Steroids induce remission but never maintain remission
  • 5PSC + UC = high CRC risk
  • 6Terminal ileum Crohn causes B12 deficiency, bile acid diarrhea, gallstones, calcium oxalate stones
  • 7Exclude C difficile before treating an IBD flare

Put your reading into practice

Topic-specific question practice is not linked for this article yet.

Choose USMLE Step 2 CK questions from the existing bank. General exam practice covers your selected topics; it is not filtered to this article. Your usual question-bank access applies.

Choose USMLE Step 2 CK practice

After your session, return to this section to revisit the reading and choose your next review.

Verified Sources & References

ACG Clinical Guideline: Ulcerative Colitis in Adults
Your learning path

Save your place and choose what comes next

sign in to save your learning

Gastroenterology & Hepatology · Article 6 of 25