351 Ch 350. Inflammatory Bowel Disease (IBD) — Crohn’s Disease and Ulcerative Colitis

IBD 包含 Crohn’s disease (CD) + ulcerative colitis (UC)，autoimmune chronic relapsing-remitting inflammation of GI；CD：transmural inflammation, skip lesions, any GI tract (mouth to anus) but ileum + colon most common，fistula + stricture + abscess complications；UC：mucosal inflammation, continuous from rectum proximally, colorectum only, no fistula；presentation：bloody diarrhea + cramping + weight loss + extraintestinal manifestations (joint, skin, eye, liver, hematologic)；diagnosis：colonoscopy + biopsy (gold standard) + fecal calprotectin + imaging (MR enterography for CD)；treatment paradigm shift 2010s-2024：biologics + small molecules era — TNF inhibitors (infliximab, adalimumab, certolizumab, golimumab), anti-integrin (vedolizumab), anti-IL-12/23 (ustekinumab), anti-IL-23 selective (risankizumab, mirikizumab), JAK inhibitors (tofacitinib, upadacitinib), S1P modulators (ozanimod, etrasimod), TYK2 inhibitors emerging；top-down approach for moderate-severe disease；colorectal cancer surveillance ↑ in long-standing colitis；Lasco trial 2024 + 2025 strategies + microbiome-based therapies + JAK/STAT pathway modulators。