溃疡性结肠炎（UC）是结肠的慢性炎症性疾病，北美地区的患病率超过每10万人中的400人。患有UC的个体寿命较短，且患有结肠切除术和结直肠癌的风险增加。UC引起结肠慢性炎症导致慢性腹泻和直肠出血，从而损害了生活质量。27%左右的UC患者会出现肠外表现，如原发性硬化性胆管炎。UC患者需要监测症状和炎症生物标志物（如粪便钙升跃蛋白），并在确诊后8年接受结肠镜检查以监测发展为异型增生的情况。通过疾病分布（如蒙特利尔分类）和疾病活动（如Mayo评分）的风险分层，可以指导UC的治疗。轻到中度UC的诱导和维持缓解的一线治疗是5-氨基水杨酸。中度到重度UC可能需要口服皮质类固醇诱导缓解作为维持缓解药物（如抗肿瘤坏死因子的生物治疗单克隆抗体[例如英夫利单抗]，α4β7整合素[维度利妥]，白细胞介素[IL-12和IL-23，如优斯坦针对其的生物制药]）和口服小分子药物来抑制占星激酶（如托法替尼）或调节神经酰胺-1-磷酸酯（奇酮酰酶）。尽管医学治疗取得了一定的进展，但这些治疗的最高反应率在临床试验中的范围为30%到60%。在确诊后的5年内，约有20%的UC患者入院，约有7%接受结肠切除手术。患病20年后，结直肠癌的风险为4.5%，与一般人群相比，UC患者患结直肠癌的风险增加1.7倍。UC患者的预期寿命约为80.5岁女性和76.7岁男性，比没有UC的人群短大约5岁。UC在北美影响约每10万人中的400人。轻度到中度UC的有效治疗是5-氨基水杨酸，而中度到重度UC可以使用针对特定炎症途径的先进治疗，包括靶向肿瘤坏死因子、α4β7整合素和IL-12和IL-23细胞因子的单克隆抗体，以及靶向占星激酶或神经酰胺-1-磷酸酯的口服小分子疗法。

Ulcerative colitis (UC) is a chronic inflammatory condition of the colon, with a prevalence exceeding 400 per 100 000 in North America. Individuals with UC have a lower life expectancy and are at increased risk for colectomy and colorectal cancer.UC impairs quality of life secondary to inflammation of the colon causing chronic diarrhea and rectal bleeding. Extraintestinal manifestations, such as primary sclerosing cholangitis, occur in approximately 27% of patients with UC. People with UC require monitoring of symptoms and biomarkers of inflammation (eg, fecal calprotectin), and require colonoscopy at 8 years from diagnosis for surveillance of dysplasia. Risk stratification by disease location (eg, Montreal Classification) and disease activity (eg, Mayo Score) can guide management of UC. First-line therapy for induction and maintenance of remission of mild to moderate UC is 5-aminosalicylic acid. Moderate to severe UC may require oral corticosteroids for induction of remission as a bridge to medications that sustain remission (biologic monoclonal antibodies against tumor necrosis factor [eg, infliximab], α4β7 integrins [vedolizumab], and interleukin [IL] 12 and IL-23 [ustekinumab]) and oral small molecules that inhibit janus kinase (eg, tofacitinib) or modulate sphingosine-1-phosphate (ozanimod). Despite advances in medical therapies, the highest response to these treatments ranges from 30% to 60% in clinical trials. Within 5 years of diagnosis, approximately 20% of patients with UC are hospitalized and approximately 7% undergo colectomy. The risk of colorectal cancer after 20 years of disease duration is 4.5%, and people with UC have a 1.7-fold higher risk for colorectal cancer compared with the general population. Life expectancy in people with UC is approximately 80.5 years for females and 76.7 years for males, which is approximately 5 years shorter than people without UC.UC affects approximately 400 of every 100 000 people in North America. An effective treatment for mild to moderate UC is 5-aminosalicylic acid, whereas moderate to severe UC can be treated with advanced therapies that target specific inflammation pathways, including monoclonal antibodies to tumor necrosis factor, α4β7 integrins, and IL-12 and IL-23 cytokines, as well as oral small molecule therapies targeting janus kinase or sphingosine-1-phosphate.