Chapter 52: Inflammatory Bowel Disease

Update Summary

February 1, 2023

The following sections, tables, and figures were updated:

• Key Concepts: upadacitinib added to key concept 8, and rizankizuman-rzaa added to key concept 11

• Beyond The Book: part d revised

• Figure 52-2: risankizumab-rzaa added

• Table 52-4: rizankizumab-rzaa and upadacitinib added

• Figure 52-3: updated based on new guidelines to include new therapies

• Table 52-5: upadacitinib and rizankizumab-rzaa added

• Adverse Drug Effects: edits made to include upadacitinib and risankizumab-rzaa

• Special Populations, Pregnancy, and Breastfeeding: information added for upadacitinib and risankizumab-rzaa

KEY CONCEPTS

• The exact cause of inflammatory bowel disease (IBD) is unknown. Proposed causes include infectious, genetic, and environmental factors, as well as alterations in intestinal epithelium function and systemic immune dysregulation.

• Ulcerative colitis (UC) is confined to the rectum and colon, causes continuous lesions, and affects primarily the mucosa and the submucosa. Crohn’s disease (CD) can involve any part of the GI tract, often causes discontinuous (skip) lesions, and is a transmural process that can result in fistulas, perforations, abscesses, or strictures.

• Common GI complications of IBD include rectal fissures, fistulas (CD), perirectal abscess (UC), toxic megacolon (UC), and colon cancer. Extraintestinal manifestations include hepatobiliary complications, arthritis, uveitis, skin lesions (including erythema nodosum and pyoderma gangrenosum), osteoporosis, anemia, and aphthous ulcerations of the mouth.

• The severity of UC may be assessed by stool frequency, presence of blood in stool, fever, pulse, hemoglobin, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), abdominal tenderness, and radiologic or endoscopic findings. The severity of CD can be assessed using similar parameters, in addition to the CD Activity Index, which includes stool frequency, presence of blood in stool, endoscopic appearance, and physician’s global assessment.

• The goals of IBD treatment are resolution of acute inflammation and complications, alleviation of systemic manifestations, maintenance of remission, and improvement in quality of life (QOL).

• The first line of treatment for mild-to-moderate extensive UC consists of oral aminosalicylates (ASAs) or oral controlled-release budesonide with prednisone as an alternative. Mesalamine enemas or suppositories are preferred for distal disease. Mesalamine is less effective for CD. Controlled-release budesonide or a tapering course of prednisone with or without azathioprine is preferred as a first-line agent for mild-to-moderate CD confined to the terminal ileum and/or ascending colon. Patients with more diffuse disease can be managed by a tapering course of prednisone with or with azathioprine.

• Systemic corticosteroids are often required for acute moderate to severe UC or CD. The duration of steroid use should be minimized and the dose tapered gradually over 3 to 4 weeks if possible.

• Infliximab, adalimumab, golimumab, ozanimod, and vedolizumab are treatment options for high-risk or moderate-to-severe active UC in outpatients and for those patients with UC who are corticosteroid ...