of the disease is one of relapsing and remitting mucosal inflammation. Based on population-based cohort studies, the majority of patients with UC have a mild to moderate course, generally most active at diagnosis and then in varying periods of remission or mild activity. Approximately 15% patients may experience an aggressive course, and 20% of these patients may require hospitalization for severe disease activity.2,3 The 5- and 10-year cumulative risk of colectomy is 10%–15%, primarily limited to patients with moderate to severe disease activity; a subset of hospitalized patients with acute severe ulcerative colitis (ASUC) have short-term colectomy rates of 25%–30%.3 Predictors of an aggressive disease course and colectomy are the following: young age at diagnosis (90 beats/min, temperature >37.8C, hemoglobin 6 >10 Blood in stool Intermittent Frequent Continuous Temperature, C Normal >37.5 >37.5 Pulse, beats/min Normal >90 >90 Hemoglobin Normal 30 >30 Colonic features on radiograph None Air, edematous wall, thumbprinting Colonic dilation Clinical signs None Abdominal tenderness Abdominal distention and tenderness Variable Mayo score for UC Definition Score Variable Definition Score Stool pattern Normal no. of daily bowel movements 0 Endoscopic findings Normal/inactive colitis 0 1–2 more bowel movements than normal 1 Erythema, decreased vascularity 1 3–4 more bowel movements than normal 2 Friability, marked erythema, erosions 2 5 or more bowel movements than normal 3 Ulcerations, severe friability, spontaneous bleeding 3 Most severe rectal bleeding of the day None 0 Physician Global Assessment Normal 0 Blood streaks seen in the stool less than half of the time 1 Mild colitis 1 Blood in most stool 2 Moderate colitis 2 Pure blood passed 3 Severe colitis 3 April 2020 AGA Guidelines on Management of Moderate to Severe UC 1451 CLINICAL PRACTICE GUIDELINES prepare the background information for the guideline and the accompanying technical review.1 Optimal understanding of the guideline will be enhanced by reading the applicable portions of the technical review. The guideline panel and the authors of the technical review met face to face on December 14, 2018 to discuss the findings from the technical review. The guideline authors subsequently formulated the guideline recommendations using the GRADE evidence-to-decision framework guidance. New evidence was presented to the guideline panel by the technical review team on October 16, 2019, and was reviewed and approved in a virtual face-to-face meeting on November 1, 2019. Although the quality of evidence (Table 2) was a key factor in determining the strength of the recommendations (Table 3), the panel also considered the balance between benefit and harm of interventions, patients’ values and preferences, and overall resource utilization. The recommendations, quality of evidence, and strength of recommendations are summarized in Table 4. Recommendation 1. In adult outpatients with moderate to severe ulcerative colitis, the AGA recommends using infliximab, adalimumab, golimumab, vedolizumab, tofacitinib, or ustekinumab over no treatment. (Strong recommendation, moderate quality evidence) The panel recommends treating adult outpatients with moderate to severe UC with infliximab, adalimumab, golimumab, vedolizumab, tofacitinib, or ustekinumab over no treatment for the induction and maintenance of remission. There were 16 randomized controlled trials (RCTs) comparing the TNF-a antagonists, vedolizumab, tofacitinib, and ustekinumab to placebo (see technical review). Induction of remission was assessed at 6–8 weeks and maintenance of remission was evaluated at 30–54 weeks. All active interventions were superior to placebo for induction of remission, regardless of prior biologic exposure (infliximab: relative risk [RR], 2.85; 95% confidence interval [CI], 2.11– 3.86; adalimumab: RR, 1.62; 95% CI, 1.15–2.29; golimumab: RR, 2.49; 95% CI, 1.58–3.93; vedolizumab: RR, 2.22; 95% CI, 1.36–3.64; tofactinib: RR, 3.22; 95% CI, 2.03–5.08; and ustekinumab: RR, 2.91; 95% CI, 1.72–4.94). Likewise, all active interventions were superior to