BSG 2025 - IBD Guidelines (Adults)

Citation: Moran GW, et al., on behalf of the BSG IBD guideline development group. “British Society of Gastroenterology guidelines on the management of inflammatory bowel disease in adults.” Gut 2025;74:s1–s101. Published 23 June 2025; updates the 2019 BSG IBD guideline. Source file: raw/Moran 2025 - BSG Guidelines on the Management of IBD in Adults.pdf.

Type: Society clinical practice guideline — GRADE-based recommendations plus non-GRADE “Good Practice Statements” (GPS 1–114) for areas where formal evidence grading wasn’t feasible. By far the broadest of the three guidelines in this batch (102 pages vs. 38 for ACG 2025 - Ulcerative Colitis Guideline and 37 for AGA 2024 - Moderate-to-Severe UC Pharmacotherapy Guideline) — covers both UC and Crohn’s disease, plus extensive cross-cutting content neither of the other two guidelines addresses.

Scope

Full adult IBD management: diagnosis/monitoring for both diseases (endoscopic and histologic scoring systems, imaging modality selection), UC treatment ladder through ASUC and surgery/pouchitis, full Crohn’s disease medical and surgical management (previously entirely absent from primary-guideline sourcing in this wiki — Crohn’s had only textbook-chapter content), perianal Crohn’s disease, post-surgical Crohn’s recurrence prevention, therapeutic drug monitoring (detailed, both purine analogue metabolite and biologic trough-level tables), superadded infectious colitis (CMV, C. difficile) in the IBD-specific context, iron deficiency anaemia, pregnancy/pre-conception/ post-partum (far more detailed than either other guideline, both of which largely exclude this topic), pain and fatigue management, primary sclerosing cholangitis-IBD, patient education and digital health, smoking, and IBD-associated spondyloarthropathy/extraintestinal joint disease.

Key points — Crohn’s disease medical management (the wiki’s single biggest gap, now closed)

Prior to this ingest, Crohn Disease had zero primary-literature/guideline backing for its medical therapy — everything came from the Sabiston textbook chapters. This guideline provides full GRADE-based recommendations:

• Adalimumab: suggested (conditional, moderate certainty/magnitude) for induction and maintenance, explicitly recommended in combination with a purine analogue — network meta-analysis showed combination lowers NNT for remission from 4 to 2 and improves response by 7% over monotherapy. No RCT re-randomised for maintenance beyond 12 months, so long-term combination duration is individualised.
• Infliximab: similarly suggested (conditional, moderate certainty/magnitude) with combination with a purine analogue also recommended (maintenance magnitude ~20% higher with combination than monotherapy). Biosimilars considered equivalent to originator.
• Ustekinumab: suggested (conditional, moderate certainty/magnitude) for induction and maintenance — can be used after purine analogue and/or anti-TNF failure.
• Risankizumab (anti-IL-23p19): suggested (conditional, low certainty, small magnitude) — newly approved for Crohn’s; the SEQUENCE head-to-head trial vs. ustekinumab in anti-TNF-experienced patients showed non-inferiority for clinical remission at week 24 and superiority for endoscopic remission at week 48.
• Upadacitinib: suggested (conditional, low certainty, small magnitude) — the first oral agent shown effective for both inducing and maintaining Crohn’s remission. Recommended only after anti-TNF failure/intolerance/contraindication given its boxed warning (VTE/MACE in higher-risk patients, shared class-wide caution with the JAK-inhibitor safety signal discussed in ACG 2025 - Ulcerative Colitis Guideline).
• Vedolizumab: NOT suggested for induction or maintenance in Crohn’s disease (conditional recommendation against, low certainty, trivial magnitude) — a genuinely different stance than its position in UC (where it’s a first-line advanced therapy per both ACG and AGA guidelines). The guideline is explicit that a trivial effect size was seen across all direct evidence regardless of biologic-naive/-exposed status, though it doesn’t preclude use in individual patients via shared decision-making — recommendation cannot be extended to combination with purine analogues due to lack of evidence.
• Antibiotics: NOT suggested (conditional, high certainty, trivial magnitude) — no individual antibiotic or combination robustly studied; class-wide effect on induction is small/trivial, no evidence for maintenance.
• Probiotics: NOT suggested (conditional, very low certainty) — insufficient evidence either way.
• Exclusive enteral nutrition (EEN): not formally graded for adults (well-established in pediatric Crohn’s, ~73% remission rates, but adult evidence is a Cochrane review showing no difference vs. steroids without being able to draw firm conclusions due to very low certainty). A detailed practical protocol is given (GPS 66) for preoperative use specifically — 6 weeks preoperative EEN associated with lower postoperative abscess/leak rates and lower CRP in observational data.
• Therapeutic drug monitoring specifics (adds real numbers to what ACG 2025 - Ulcerative Colitis Guideline only discussed qualitatively): target purine analogue metabolites (6-TGN 235–450 pmol/8×10⁸ RBCs, MMP <5700 pmol/8×10⁸ RBCs); PANTS-study-derived optimal anti-TNF trough targets specifically for later time points (weeks 14+) are 6.1–10.0 mg/L for infliximab and 10.1–12.0 mg/L for adalimumab — though the guideline notes insufficient evidence to formally recommend targeting such high levels routinely. TPMT/NUDT15 pharmacogenomic testing before starting purine analogues (NUDT15 not yet widely available in the UK at time of writing).

Key points — Perianal and post-surgical Crohn’s disease

• Perianal Crohn’s: multidisciplinary workup (pelvic MRI + exam under anaesthesia + endoanal ultrasound — MRI as an adjunct to EUA by an experienced colorectal surgeon is a Good Practice Statement); presence of proctitis worsens fistula-healing prognosis (OR 2.85 for poor surgical outcome). Seton placement to control sepsis, timing of removal individualised. Infliximab suggested as first-line biologic for perianal Crohn’s, started as soon as adequate sepsis drainage achieved — pooled anti-TNF data show RR 1.94 for fistula induction of remission and 1.79 for maintenance vs. placebo. The PISA-II trial (only published surgical RCT since the last BSG guideline) found MRI-assessed fistula closure higher with combined surgery (advancement flap/LIFT) than anti-TNF alone (12% vs 9%). Reparative surgery (advancement flap, LIFT) may be considered in selected patients in a multidisciplinary setting. Refractory severe perianal disease affecting quality of life should be offered faecal stream diversion (defunctioning stoma) — reversal rates are low and proctectomy may ultimately be required. A phase III trial of mesenchymal stem cell therapy (Cx601/darvadstrocel) failed its primary combined-remission endpoint at 24 weeks despite promising phase II signal.
• Post-surgical Crohn’s recurrence prevention: anti-TNF (infliximab or adalimumab) or vedolizumab suggested after ileocolonic resection for patients with significant recurrence risk factors (young age at diagnosis, active smoking, penetrating disease, perianal disease, multiple prior surgeries), or by patient preference, or with endoscopic evidence of recurrence at 6 months — recommended to start within 90 days post-surgery where indicated (conditional, low certainty, large magnitude — NMA data show adalimumab HR 0.1 and infliximab HR 0.36 for preventing clinical relapse vs. placebo). 5-ASA and purine analogue monotherapy are NOT suggested for post-surgical maintenance — trivial effect size (NNT 13–14) despite reaching statistical significance in some trials. Endoscopic recurrence is best assessed by ileocolonoscopy at 6 months post-resection using the Rutgeerts score.
• Withdrawal of therapy: infliximab withdrawal after ≥1 year of stable remission is NOT suggested (conditional, moderate certainty/magnitude) — both RCTs examining this (SPARE, STOP-IT) showed elevated relapse risk on withdrawal (roughly 1 in 3 patients relapse within 1–2 years), though retreatment on relapse is usually successful. By contrast, withdrawing the immunomodulator while continuing anti-TNF is not associated with a significant relapse-risk increase if attempted after >2 years of combination therapy and >6 months of corticosteroid-free remission.
• Non-surgical stricture management: CREOLE study — adalimumab successful (no escalation to steroids/dilation/surgery) in 64% of symptomatic ileal Crohn’s strictures at 24 weeks; a prognostic score based on clinical and MRE features predicts response. Endoscopic balloon dilation appropriate for ileocolonic anastomotic strictures <4cm without sharp angulation, though most patients need repeat dilation and complication/recurrence rates are higher for longer strictures.
• Surgical management of strictures: strictureplasty recommended as an alternative to resection for strictures <10cm (matches existing wiki teaching from the Sabiston small-bowel chapter); active inflammation at the stricture site doesn’t preclude strictureplasty. If multiple strictures cluster in a segment with adequate remaining healthy bowel, single resection may be preferable to multiple strictureplasties.
• Perioperative optimization (Good Practice Statements): laparoscopic resection should be considered for localised ileocaecal disease; malnutrition screening/correction as part of preoperative optimisation (immune-enhancing nutritional supplements reduce postoperative complications, OR 0.26); corticosteroids should be stopped or minimised preoperatively where possible (≥20mg prednisolone associated with increased complications; equivalent IV hydrocortisone given if steroid-dependent and NPO); immunosuppressive agents (purine analogues, methotrexate) and biologics can be continued perioperatively — reassuring large observational studies (PUCCINI, French REMIND) found no significant postoperative infection increase with anti-TNF exposure, similarly reassuring (though smaller) data for vedolizumab and ustekinumab; JAK inhibitor perioperative safety data are limited (one retrospective series: 13.2% VTE rate after tofacitinib exposure before colectomy — prolonged VTE prophylaxis suggested). VTE prophylaxis (pharmacological) recommended for all IBD patients admitted for acute illness or surgery unless contraindicated — IBD carries ~2x baseline VTE risk, further elevated with active inflammation (HR 8.4) and hospitalisation; risk persists 60–90 days post-discharge, and UK practice extends prophylaxis post-discharge after major abdominal surgery.

Key points — cross-cutting topics (apply to both UC and Crohn’s)

• Superadded infection: CMV present in up to 10–30% of steroid-refractory IBD; diagnosis via colonic tissue immunohistochemistry or PCR (preferred over serum PCR/antigen, which don’t correlate well with colonic infection); treatment is IV ganciclovir 5mg/kg BID for 5–10 days then oral valganciclovir to complete a 2–3 week course, continuing background immunosuppression unless disseminated disease. C. difficile — IBD is an independent risk factor for CDI regardless of antibiotic/PPI exposure; vancomycin or fidaxomicin for 10 days (add IV metronidazole for severe cases); FMT for recurrent CDI (matches and adds IBD-specific context to existing wiki coverage on Infectious Colitis).
• Iron deficiency anaemia: oral iron first-line if tolerated in inactive disease (max 100mg elemental iron/day — systemic inflammation impairs absorption in active disease, where IV iron is preferred); trivial difference in efficacy between IV and oral routes but IV carries more adverse events; ferritin <100 µg/L may still reflect deficiency in the presence of inflammation — transferrin saturation more reliable then.
• Pregnancy (a topic ACG 2025 - Ulcerative Colitis Guideline explicitly excludes, and AGA 2024 - Moderate-to-Severe UC Pharmacotherapy Guideline only briefly touches): aim for ≥3 months corticosteroid-free remission before conception; continue anti-TNF throughout pregnancy (reduces relapse risk, no increased adverse pregnancy outcome vs. non-pregnant IBD patients, though earlier retrospective data links continued anti-TNF beyond 24 weeks to higher maternal infection rates); vedolizumab/ustekinumab likely low risk but less data. JAK inhibitors (tofacitinib, upadacitinib, filgotinib) and S1P modulators (ozanimod, etrasimod) are contraindicated during conception, pregnancy, and lactation — stop ≥3 months before conception. Methotrexate teratogenic, stop ≥3–6 months pre-conception in both sexes. Live vaccines (including BCG) withheld until 12 months of age in infants with in-utero biologic exposure — several fatal disseminated BCG infections reported in infants vaccinated <1 month old after infliximab/adalimumab exposure. Breastfeeding considered low-risk/continue for essentially all standard IBD medications except JAK inhibitors and S1P modulators. Mode of delivery: caesarean generally preferred for active perianal disease or IPAA/ileorectal anastomosis; otherwise obstetric/patient-preference-driven.
• Primary sclerosing cholangitis-IBD: a distinct phenotype (pan-colonic/right-sided, rectal-sparing, backwash ileitis, milder symptomatic course but higher rectal-sparing and dysplasia risk) present in a majority of PSC patients (mostly UC). Confers a 3-4x increased colorectal dysplasia/cancer risk vs. IBD alone (OR 3.24) and a 4x risk vs. non-IBD PSC patients diagnosed under 40. Annual surveillance colonoscopy from 8 years after IBD symptom onset, or from PSC diagnosis if that comes first (lifelong high-risk category, continues even post-liver-transplant). Higher pouchitis rates after IPAA in PSC-IBD (14–90% across studies) though pouch failure rates are similar to non-PSC IBD.
• Extraintestinal joint disease / spondyloarthropathy: anti-TNF is recommended first-line for concurrent axial/peripheral SpA and IBD. Tofacitinib effective for UC+PsA but not licensed for Crohn’s in the UK; upadacitinib licensed across Crohn’s/UC/PsA/axial SpA; ustekinumab and risankizumab licensed for IBD+PsA/PsO but not for axial SpA. Etanercept, abatacept, secukinumab, ixekizumab, and brodalumab should be avoided in IBD patients with concurrent SpA — lack of IBD efficacy and risk of causing IBD exacerbation (etanercept specifically flagged as associated with IBD relapses when used for SpA). Anti-TNF therapy itself can paradoxically induce psoriasis/psoriasiform rash in 2–5% of treated IBD patients (risk factors: smoking, ileocolonic Crohn’s, female sex, younger age at anti-TNF initiation) — should not automatically prompt anti-TNF discontinuation, but consider topical management, drug switch within class, or biologic class change depending on severity.
• Smoking: reiterates the opposite-direction effect already in the wiki (Inflammatory Bowel Disease) — smoking worsens Crohn’s course (2.5x repeat-surgery risk, 2x recurrence risk) and improves/is protective in UC (though cessation remains strongly advised regardless, given smoking’s other harms — this is a Good Practice Statement, “in no circumstance should smoking be advocated as a therapeutic option”). New: specific guidance that light/passive smoking (<10 cigarettes/day) does not meaningfully reduce Crohn’s harms, and that vaping, while not risk-free, is an acceptable harm-reduction bridge for smokers actively quitting (not for never-smokers or those under 18).
• Patient education, digital health, pain/fatigue management: education programmes recommended as adjuncts (modest, inconsistent evidence for hard outcomes but improve knowledge/self-management scores); digital/telehealth monitoring may reduce hospital attendance without clear disease-activity benefit; chronic pain in IBD should prompt exclusion of stricturing disease/abscess/uncontrolled inflammation before treating as functional/IBS-overlap (CBT, gut hypnotherapy suggested as adjuncts); fatigue without a correctable cause may warrant non-pharmacological intervention (psychoeducation, structured exercise, stress management — evidence quality low throughout).

Limitations

• By far the largest and most heterogeneous of the three guidelines ingested this session — this wiki page and the disease-page updates it feeds prioritize the highest-value new content (Crohn’s medical/surgical management, TDM specifics, pregnancy, PSC-IBD, perianal disease) over exhaustive transcription of every Good Practice Statement (114 total) or every UC-specific recommendation, since the UC ground is already well covered by ACG 2025 - Ulcerative Colitis Guideline and AGA 2024 - Moderate-to-Severe UC Pharmacotherapy Guideline. Stephen should flag if a specific BSG UC recommendation is needed and it isn’t here yet — it may simply not have been prioritized during this ingest rather than absent from the source.
• Vedolizumab’s “not suggested” stance in Crohn’s disease here is a genuine, evidence-based divergence from its favorable UC positioning in the other two guidelines — this is a real disease-specific efficacy difference (trivial effect size in Crohn’s trials specifically), not a methodology disagreement like the ACG/AGA NMA split.
• Many Good Practice Statements are explicitly not GRADE-graded (evidence didn’t fit the framework) — treat these as expert consensus, not formal evidence-based recommendations, even though they’re presented with the same visual weight as GRADE statements in the source document.
• Reference list (pages ~87–101) not reviewed in detail; specific primary trials named here (SPARE, STOP-IT, PISA-II, CREOLE, SEQUENCE, PANTS, PUCCINI, TABACROHN, etc.) are relayed as the guideline describes them, not independently verified against their own publications.

Relevance

The single biggest contribution: closes the wiki’s main IBD asymmetry — Crohn Disease now has primary-guideline-sourced medical/surgical management to match what Ulcerative Colitis gained from the ACG and AGA guidelines. Also substantially enriches Inflammatory Bowel Disease with cross-cutting content (TDM, pregnancy, PSC-IBD, extraintestinal SpA management, smoking) that applies regardless of UC/Crohn’s distinction. See Crohn Disease and Inflammatory Bowel Disease for the disease-page updates this ingest produced.