IBD, in full.

Two current US guidelines govern Crohn's disease and should be read together. ACG 2025 (Lichtenstein et al.) remains the reference for diagnosis, mild-to-moderate disease, perianal, postoperative and abscess management. DIAGNOSIS: fecal calprotectin (>50-100 μg/g) separates inflammatory from noninflammatory disease of the colon. Workup is ileocolonoscopy with biopsies, including uninvolved mucosa, plus small-bowel imaging. CTE and MRE are comparable; prefer MRE in patients <35 y and when serial exams are likely. Intestinal ultrasound is an ungraded adjunct. Do routine CRC surveillance in Crohn's colitis. MILD-TO-MODERATE: recommend against oral mesalamine; sulfasalazine only for symptomatic mild colonic CD; ileal-release budesonide 9 mg for induction in ileocecal disease but not for maintenance. MODERATE-TO-SEVERE (AGA Living Guideline, Scott et al., Gastroenterology 2025;169(7):1397-1448, 16 recommendations: 1 strong, 9 conditional, 6 knowledge gaps; updated quarterly, adult outpatients only): RECOMMEND infliximab, adalimumab, ustekinumab, risankizumab, mirikizumab, guselkumab or upadacitinib over no treatment; SUGGEST certolizumab pegol or vedolizumab over no treatment. Advanced-therapy-naive: suggest higher-efficacy agents (infliximab, adalimumab, vedolizumab, ustekinumab, risankizumab, mirikizumab, guselkumab) over lower-efficacy ones (certolizumab pegol, upadacitinib). Prior advanced-therapy (especially anti-TNF) exposure: suggest higher- or intermediate-efficacy agents (adalimumab, risankizumab, guselkumab, upadacitinib; ustekinumab, mirikizumab) over lower-efficacy ones (vedolizumab, certolizumab pegol). Suggest against thiopurine monotherapy for induction; suggest it for maintenance of remission. Suggest SC/IM methotrexate monotherapy; suggest against oral methotrexate. In thiopurine-naive patients starting infliximab, suggest infliximab + thiopurine over infliximab alone. No recommendation on IFX + MTX, adalimumab + immunomodulator, or non-TNF biologic + immunomodulator. After ≥6 months of steroid-free remission on anti-TNF + immunomodulator, suggest withdrawing the immunomodulator and suggest against withdrawing the anti-TNF. SUGGEST upfront advanced therapy over step-up therapy (corticosteroids and/or immunomodulator first). No recommendation on treating to endoscopic vs symptomatic remission. The ACG 2025 moderate-to-severe recommendations (anti-TNF, IFX + thiopurine combination and IL-12/23/IL-23 agents, each strong/moderate; upadacitinib after anti-TNF exposure; steroids for short-term induction only; TPMT/NUDT15 testing before thiopurines) still stand alongside AGA. ACG perianal (infliximab first; drain abscesses and place setons before escalating), postoperative (endoscopy at 6-12 months; anti-TNF strong, vedolizumab conditional in high-risk patients) and intra-abdominal abscess (>2 cm: antibiotics plus drainage, hold immunosuppression) positions are unchanged. THERAPEUTIC ENDOSCOPY (AGA Clinical Practice Update, CGH 2026; details below come from AGA news coverage, not the full text, and are ungraded advice): get cross-sectional imaging before the procedure. Endoscopic balloon dilation is first-line for short strictures (about ≤4-5 cm) with few risk factors (fistula, prestenotic dilation >5 cm, high CRP, prior anti-TNF). Longer or multiple strictures, or ≥3 risk factors, favor surgery.

In IBD patients who are pregnant or planning pregnancy, the goal remains stable steroid-free remission before conception, throughout pregnancy, and postpartum, because active disease (not medication) is the dominant driver of adverse maternal/fetal outcomes (preterm birth, growth restriction, low birth weight, hypertensive disease, cesarean birth). Continue effective maintenance therapy on schedule through pregnancy and lactation, mesalamine, thiopurines, and biologics/biosimilars (anti-TNF, vedolizumab, ustekinumab), rather than stopping for pregnancy; discontinuation raises postpartum flare and complication risk. SCOPE OF THE CITED SOURCE, read this before extending the sentence above: the IL-23p19 antagonists are NOT addressed by the 2019 AGA IBD Parenthood Project pathway, which predates their IBD indications entirely (Drugs@FDA efficacy-supplement approvals: risankizumab for Crohn's disease June 2022 and for ulcerative colitis June 2024; mirikizumab for ulcerative colitis October 2023 and for Crohn's disease January 2025; guselkumab for ulcerative colitis September 2024 and for Crohn's disease March 2025). Continuing risankizumab, guselkumab or mirikizumab through pregnancy and lactation is EXPERT PRACTICE extrapolated from the other monoclonal antibodies, it is not a recommendation of the cited document, and it must not be presented as one. All three FDA labels state that the available human pregnancy data are insufficient to establish a drug-associated risk of major birth defects, miscarriage or other adverse maternal or fetal outcomes, and all three carry a pregnancy exposure registry: enrol the patient and document the shared decision. Avoid JAK inhibitors during pregnancy and lactation due to insufficient reproductive safety data. For suspected flare, favor fecal calprotectin plus intestinal ultrasound or non-gadolinium MRI over CT, reserve endoscopy for when it will change management, and use corticosteroids or biologic initiation/switching as clinically necessary. Recommend cesarean delivery for active perianal Crohn's disease and now also consider cesarean for patients with a prior ileal pouch-anal anastomosis (IPAA) to protect pouch function. New elements versus prior guidance: low-dose aspirin started at 12-16 weeks gestation to reduce preeclampsia risk, structured VTE risk monitoring pre-delivery and postpartum, and explicit endorsement of breastfeeding while on biologic therapy. Multidisciplinary GI/MFM coordination is maintained throughout.

Outpatient positioning is unchanged from the ACG 2025 UC guideline and the AGA living guideline for moderate-to-severe UC. Confirm UC with endoscopy showing continuous colonic inflammation from the rectum plus histology, after excluding infection with two-step C. difficile testing. Treat mild-moderate disease with 5-ASA chosen by route and extent: suppository for proctitis, enema for left-sided disease, oral plus rectal for extensive disease. If 5-ASA fails, treat as moderate-to-severe rather than stepping up gradually. Position advanced therapy by efficacy tier, not by an anti-TNF-first rule. Advanced-therapy-naive, higher efficacy: infliximab, vedolizumab, ozanimod, etrasimod, upadacitinib, risankizumab, guselkumab. Intermediate: golimumab, ustekinumab, tofacitinib, filgotinib, mirikizumab. Lower: adalimumab. Previously TNF-exposed, higher efficacy: tofacitinib, upadacitinib, ustekinumab. Lower: adalimumab, vedolizumab, ozanimod, etrasimod. After anti-TNF primary non-response, switch mechanism rather than cycling within the class. Treat to target (STRIDE-II): endoscopic improvement, Mayo endoscopic subscore 0-1. Begin CRC surveillance 8-10 years after diagnosis for extensive or left-sided disease; isolated proctitis follows average-risk screening. Inpatient care now follows the 2026 AGA Clinical Practice Update (13 best-practice statements). Admit for severe symptoms refractory to outpatient therapy, suspected complications (obstruction, abscess, toxic megacolon) or significant malnutrition, and identify acute severe UC by Truelove-Witts. Give every patient admitted with diarrhea two-step C. difficile testing. Test for CMV, with early endoscopy, if symptoms worsen, the patient is systemically toxic or disease is steroid-refractory. Give routine VTE prophylaxis with LMWH or fondaparinux unless contraindicated, and individualize post-discharge extension. Give IV methylprednisolone 60 mg/day or equivalent; the AGA living guideline says 40-60 mg/day, and higher doses add no benefit. Do not give adjunctive antibiotics without infection. Involve surgery early. Assess response by day 3 (72 h) using stool frequency and CRP (Oxford criteria); do not continue IV steroids beyond about 7 days without response. Rescue steroid non-responders with infliximab (accelerated or intensified dosing in selected patients with high inflammatory burden or protein-losing colopathy), cyclosporine, or a JAK inhibitor at standard or intensified dosing, or with colectomy. Before discharge, the response should be stable and a transition plan should be in place.

Outpatient positioning is unchanged from the ACG 2025 UC guideline and the AGA living guideline for moderate-to-severe UC. Confirm UC with endoscopy showing continuous colonic inflammation from the rectum plus histology, after excluding infection with two-step C. difficile testing. Treat mild-moderate disease with 5-ASA chosen by route and extent: suppository for proctitis, enema for left-sided disease, oral plus rectal for extensive disease. If 5-ASA fails, treat as moderate-to-severe rather than stepping up gradually. Position advanced therapy by efficacy tier, not by an anti-TNF-first rule. Advanced-therapy-naive, higher efficacy: infliximab, vedolizumab, ozanimod, etrasimod, upadacitinib, risankizumab, guselkumab. Intermediate: golimumab, ustekinumab, tofacitinib, filgotinib, mirikizumab. Lower: adalimumab. Previously TNF-exposed, higher efficacy: tofacitinib, upadacitinib, ustekinumab. Lower: adalimumab, vedolizumab, ozanimod, etrasimod. After anti-TNF primary non-response, switch mechanism rather than cycling within the class. Treat to target (STRIDE-II): endoscopic improvement, Mayo endoscopic subscore 0-1. Begin CRC surveillance 8-10 years after diagnosis for extensive or left-sided disease; isolated proctitis follows average-risk screening. Inpatient care now follows the 2026 AGA Clinical Practice Update (13 best-practice statements). Admit for severe symptoms refractory to outpatient therapy, suspected complications (obstruction, abscess, toxic megacolon) or significant malnutrition, and identify acute severe UC by Truelove-Witts. Give every patient admitted with diarrhea two-step C. difficile testing. Test for CMV, with early endoscopy, if symptoms worsen, the patient is systemically toxic or disease is steroid-refractory. Give routine VTE prophylaxis with LMWH or fondaparinux unless contraindicated, and individualize post-discharge extension. Give IV methylprednisolone 60 mg/day or equivalent; the AGA living guideline says 40-60 mg/day, and higher doses add no benefit. Do not give adjunctive antibiotics without infection. Involve surgery early. Assess response by day 3 (72 h) using stool frequency and CRP (Oxford criteria); do not continue IV steroids beyond about 7 days without response. Rescue steroid non-responders with infliximab (accelerated or intensified dosing in selected patients with high inflammatory burden or protein-losing colopathy), cyclosporine, or a JAK inhibitor at standard or intensified dosing, or with colectomy. Before discharge, the response should be stable and a transition plan should be in place.

Two current US guidelines govern Crohn's disease and should be read together. ACG 2025 (Lichtenstein et al.) remains the reference for diagnosis, mild-to-moderate disease, perianal, postoperative and abscess management. DIAGNOSIS: fecal calprotectin (>50-100 μg/g) separates inflammatory from noninflammatory disease of the colon. Workup is ileocolonoscopy with biopsies, including uninvolved mucosa, plus small-bowel imaging. CTE and MRE are comparable; prefer MRE in patients <35 y and when serial exams are likely. Intestinal ultrasound is an ungraded adjunct. Do routine CRC surveillance in Crohn's colitis. MILD-TO-MODERATE: recommend against oral mesalamine; sulfasalazine only for symptomatic mild colonic CD; ileal-release budesonide 9 mg for induction in ileocecal disease but not for maintenance. MODERATE-TO-SEVERE (AGA Living Guideline, Scott et al., Gastroenterology 2025;169(7):1397-1448, 16 recommendations: 1 strong, 9 conditional, 6 knowledge gaps; updated quarterly, adult outpatients only): RECOMMEND infliximab, adalimumab, ustekinumab, risankizumab, mirikizumab, guselkumab or upadacitinib over no treatment; SUGGEST certolizumab pegol or vedolizumab over no treatment. Advanced-therapy-naive: suggest higher-efficacy agents (infliximab, adalimumab, vedolizumab, ustekinumab, risankizumab, mirikizumab, guselkumab) over lower-efficacy ones (certolizumab pegol, upadacitinib). Prior advanced-therapy (especially anti-TNF) exposure: suggest higher- or intermediate-efficacy agents (adalimumab, risankizumab, guselkumab, upadacitinib; ustekinumab, mirikizumab) over lower-efficacy ones (vedolizumab, certolizumab pegol). Suggest against thiopurine monotherapy for induction; suggest it for maintenance of remission. Suggest SC/IM methotrexate monotherapy; suggest against oral methotrexate. In thiopurine-naive patients starting infliximab, suggest infliximab + thiopurine over infliximab alone. No recommendation on IFX + MTX, adalimumab + immunomodulator, or non-TNF biologic + immunomodulator. After ≥6 months of steroid-free remission on anti-TNF + immunomodulator, suggest withdrawing the immunomodulator and suggest against withdrawing the anti-TNF. SUGGEST upfront advanced therapy over step-up therapy (corticosteroids and/or immunomodulator first). No recommendation on treating to endoscopic vs symptomatic remission. The ACG 2025 moderate-to-severe recommendations (anti-TNF, IFX + thiopurine combination and IL-12/23/IL-23 agents, each strong/moderate; upadacitinib after anti-TNF exposure; steroids for short-term induction only; TPMT/NUDT15 testing before thiopurines) still stand alongside AGA. ACG perianal (infliximab first; drain abscesses and place setons before escalating), postoperative (endoscopy at 6-12 months; anti-TNF strong, vedolizumab conditional in high-risk patients) and intra-abdominal abscess (>2 cm: antibiotics plus drainage, hold immunosuppression) positions are unchanged. THERAPEUTIC ENDOSCOPY (AGA Clinical Practice Update, CGH 2026; details below come from AGA news coverage, not the full text, and are ungraded advice): get cross-sectional imaging before the procedure. Endoscopic balloon dilation is first-line for short strictures (about ≤4-5 cm) with few risk factors (fistula, prestenotic dilation >5 cm, high CRP, prior anti-TNF). Longer or multiple strictures, or ≥3 risk factors, favor surgery.

Two current US guidelines govern Crohn's disease and should be read together. ACG 2025 (Lichtenstein et al.) remains the reference for diagnosis, mild-to-moderate disease, perianal, postoperative and abscess management. DIAGNOSIS: fecal calprotectin (>50-100 μg/g) separates inflammatory from noninflammatory disease of the colon. Workup is ileocolonoscopy with biopsies, including uninvolved mucosa, plus small-bowel imaging. CTE and MRE are comparable; prefer MRE in patients <35 y and when serial exams are likely. Intestinal ultrasound is an ungraded adjunct. Do routine CRC surveillance in Crohn's colitis. MILD-TO-MODERATE: recommend against oral mesalamine; sulfasalazine only for symptomatic mild colonic CD; ileal-release budesonide 9 mg for induction in ileocecal disease but not for maintenance. MODERATE-TO-SEVERE (AGA Living Guideline, Scott et al., Gastroenterology 2025;169(7):1397-1448, 16 recommendations: 1 strong, 9 conditional, 6 knowledge gaps; updated quarterly, adult outpatients only): RECOMMEND infliximab, adalimumab, ustekinumab, risankizumab, mirikizumab, guselkumab or upadacitinib over no treatment; SUGGEST certolizumab pegol or vedolizumab over no treatment. Advanced-therapy-naive: suggest higher-efficacy agents (infliximab, adalimumab, vedolizumab, ustekinumab, risankizumab, mirikizumab, guselkumab) over lower-efficacy ones (certolizumab pegol, upadacitinib). Prior advanced-therapy (especially anti-TNF) exposure: suggest higher- or intermediate-efficacy agents (adalimumab, risankizumab, guselkumab, upadacitinib; ustekinumab, mirikizumab) over lower-efficacy ones (vedolizumab, certolizumab pegol). Suggest against thiopurine monotherapy for induction; suggest it for maintenance of remission. Suggest SC/IM methotrexate monotherapy; suggest against oral methotrexate. In thiopurine-naive patients starting infliximab, suggest infliximab + thiopurine over infliximab alone. No recommendation on IFX + MTX, adalimumab + immunomodulator, or non-TNF biologic + immunomodulator. After ≥6 months of steroid-free remission on anti-TNF + immunomodulator, suggest withdrawing the immunomodulator and suggest against withdrawing the anti-TNF. SUGGEST upfront advanced therapy over step-up therapy (corticosteroids and/or immunomodulator first). No recommendation on treating to endoscopic vs symptomatic remission. The ACG 2025 moderate-to-severe recommendations (anti-TNF, IFX + thiopurine combination and IL-12/23/IL-23 agents, each strong/moderate; upadacitinib after anti-TNF exposure; steroids for short-term induction only; TPMT/NUDT15 testing before thiopurines) still stand alongside AGA. ACG perianal (infliximab first; drain abscesses and place setons before escalating), postoperative (endoscopy at 6-12 months; anti-TNF strong, vedolizumab conditional in high-risk patients) and intra-abdominal abscess (>2 cm: antibiotics plus drainage, hold immunosuppression) positions are unchanged. THERAPEUTIC ENDOSCOPY (AGA Clinical Practice Update, CGH 2026; details below come from AGA news coverage, not the full text, and are ungraded advice): get cross-sectional imaging before the procedure. Endoscopic balloon dilation is first-line for short strictures (about ≤4-5 cm) with few risk factors (fistula, prestenotic dilation >5 cm, high CRP, prior anti-TNF). Longer or multiple strictures, or ≥3 risk factors, favor surgery.