Malcolm Tan @ibdgastrodocsg.bsky.social · 12/09/2026IBD Advanced Therapy Decision Support Tool Choosing the right advanced therapy in inflammatory bowel disease (#IBD) requires balancing disease phenotype, safety contraindications, and patient preferences. ibdadvrx.ai.studio (free to use, no log-in required) #IBD #crohns #colitis 120
Malcolm Tan @ibdgastrodocsg.bsky.social · 22/02/2026An interesting paper on ASUC, highlighting differences between populations In East Asia, even with worse endoscopic severity and lower IFX use: - lower corticosteroid failure (21.5% vs 57.2%) - lower colectomy rates (6.3% vs 29.7%) - fewer readmissions within 12 months #IBD 100
Malcolm Tan @ibdgastrodocsg.bsky.social · 20/10/2025Obefazimod in mod-severe UC - week 8 induction data presented at #UEGWeek - first in class for IBD 1/🧵 MoA: ⬆️expression of miR-124, which regulates inflammatory response & restores mucosal homeostasis. 120
Malcolm Tan @ibdgastrodocsg.bsky.social · 10/08/2025How intestinal ultrasound (IUS) changes IBD care – clinical impact, cost savings & greener healthcare 1/ #IBD is rising fast in SE Asia 📈 We need tools that are accurate, patient-friendly, and sustainable. Our SGH pilot study shows #IntestinalUltrasound ticks all 3 boxes ✅ 140
Malcolm Tan @ibdgastrodocsg.bsky.social · 27/06/2025APOLLO-CD A phase 2a induction trial of tulisokibart, an anti-TL1A monoclonal antibody, shows promising efficacy & safety in patients with moderate-to-severe Crohn’s disease (CD) refractory to prior therapies. Key findings from the APOLLO-CD study: [🔗https://doi.org/10.1016/S2468-1253(25)00071-8] 150
Malcolm Tan @ibdgastrodocsg.bsky.social · 21/06/20252025 guidelines for IBD from @amcollegegastro.bsky.social Crohn's: journals.lww.com/ajg/fulltext... UC: journals.lww.com/ajg/fulltext... #IBDSky #MedSky #GISky 061
Malcolm Tan @ibdgastrodocsg.bsky.social · 02/06/2025Checkpoint inhibitor-induced colitis (ICI-colitis): a serious, often under-recognized complication in cancer patients receiving immunotherapy. 1/ ICI-induced colitis 📈 Affects up to 30% of patients on ICIs. 🔬 This study followed 96 patients with 12-month outcomes. www.esmoopen.com/article/S205... 160
Malcolm Tan @ibdgastrodocsg.bsky.social · 01/05/2025BSG 2025 Guidelines: Colorectal Surveillance in IBD gut.bmj.com/content/earl... @bmj.com #GISky #IBDSky 031
Malcolm Tan @ibdgastrodocsg.bsky.social · 25/04/2025🧵1/ Can IBD meds be safely used after cancer? New prospective data from the SAPPHIRE Registry tackles a key concern: the safety of immunosuppressive therapy in IBD patients with prior malignancy. Let’s break down the findings. #IBDSky #GISky #OncoSky 110
Malcolm Tan @ibdgastrodocsg.bsky.social · 19/04/2025🧵1/ Can anti-TNF be safely withdrawn in patients with IBD in sustained remission? The EXIT trial (Gut, 2025). A randomized, quadruple-blind, placebo-controlled trial across 33 centers in Spain. #IBDSky #GISky 130
Malcolm Tan @ibdgastrodocsg.bsky.social · 19/04/2025A post-hoc analysis of the RISK study shows that early anti-TNF therapy can significantly reduce the risk of perianal fistulas — one of the most challenging complications. 📌 Context: 1 in 3 children with Crohn’s develop perianal fistulas (PFCs) #IBDSky #SurgSky #GISky 130
Malcolm Tan @ibdgastrodocsg.bsky.social · 14/04/2025ADMIT-ASC index for ASUC. Score of ≥3 was 84% predictive of steroid failure - CRP ≥100mg/L (1 point) - albumin ≤25g/L (1 point) - UCEIS ≥4 (1 point) or ≥7 (2 points) Will these pts benefit from early 'salvage' therapy instead of waiting till Day 3? #IBDSky #GISky gut.bmj.com/content/72/3... 021
Malcolm Tan @ibdgastrodocsg.bsky.social · 14/04/2025SES-CD for Crohn's 4 parameters: - size of ulcers - extent of ulcerated surface - extent of colitis - stenosis 5 segments: - ileum, right, transverse, left colon and rectum Endo remission: ≤2 (or <4) Accessible online calculator: www.e-guide.ecco-ibd.eu/resources/ca... #IBDSky #GISky #SurgSky 021
Malcolm Tan @ibdgastrodocsg.bsky.social · 14/04/2025Nancy index in UC. 4 grades: Nancy 0 or 1 = histologic remission. - Not a formal target to strive for but gives a good idea about activity. Easy way to remember is: - neutrophils in the mucosa = acute/active inflammation = bad #GISky #IBDSky #PathSky 021
Malcolm Tan @ibdgastrodocsg.bsky.social · 14/04/2025GRAVITI trial 🧵 Guselkumab is an IL-23 inhibitor. GRAVITI tested fully SC dosing (no IV) for both induction & maintenance in moderate-to-severe Crohn’s. N = 347 adults, randomized 1:1:1 - GUS 400 mg q4w induction → 100 mg q8w - GUS 400 mg q4w induction → 200 mg q4w #IBDSky #GISky #MedSky 120
Malcolm Tan @ibdgastrodocsg.bsky.social · 14/04/2025Can removing the appendix help prevent relapse in ulcerative colitis? The #ACCURE trial says: Yes. 🧵 ✂️ Pragmatic, open-label RCT across 22 centers (Netherlands, UK, Ireland). Patients in UC remission randomized to: ✅ Appendicectomy + standard medical therapy vs 🧪 Standard medical therapy alone 150
Malcolm Tan @ibdgastrodocsg.bsky.social · 31/03/2025malcolmtan.substack.com/p/colonprev-... @thelancet.bsky.social #GISkymalcolmtan.substack.comCOLONPREV: FIT vs Colonoscopy in an invitation-to-screen programme.(https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(25)00145-X/abstract) 000
Malcolm Tan @ibdgastrodocsg.bsky.social · 30/03/2025Real-world 12 month outcomes of anti-TNF vs UST vs VDZ in ulcerative colitis. UST group has 90% who are bio-experienced compared to VDZ and anti-TNF group (30+%), leading to: 1. High 'persistence' cos lack of options 2. 'Lower' efficacy of UST #IBDSky #GISky academic.oup.com/ecco-jcc/adv... 021
Malcolm Tan @ibdgastrodocsg.bsky.social · 29/03/2025Colorectal cancer screening: - FIT is non-inferior to colonoscopy for CRC-related deaths at 10 years n= 57404 Participation rates higher for FIT (39.9%) vs scope (31.8%) CRC-deaths similar: FIT (0.24%) vs scope (0.22%) #GISky #SurgSky @thelancet.bsky.social www.thelancet.com/journals/lan... 162
Malcolm Tan @ibdgastrodocsg.bsky.social · 23/03/2025Primary Sclerosing Cholangitis - higher risk of colorectal Ca, biliary Ca and cirrhosis - dx: MRC, histology, ALP/GGT, IBD - no proven therapy, UDCA can be considered for high-risk patients #LiverSky #GISky www.nature.com/articles/s41... 060
Malcolm Tan @ibdgastrodocsg.bsky.social · 23/02/2025Granuloma in histology: Tuberculosis vs Crohn's? TB: - necrotizing (caseating), >400 microns, multiple (>5/hpf), submucosa, confluent Crohn's: - non-necrotizing, <200 microns, infrequent, mucosa, non-confluent tl;dr: TB granulomas are larger, 'deeper' and more extensive. #IBDSky #GISky #IDSky 142
Malcolm Tan @ibdgastrodocsg.bsky.social · 16/02/2025Positioning of advanced therapies in IBD, 2025 Crohn's 1st line: anti-TNF (+IM), RZK 2nd line: RZK, UPA UC 1st line: VDZ, IFX, anti-p19 2nd line: UPA, TOFA, IFX, UST, anti-p19 @amergastroassn.bsky.social #IBDSky #GISky 151
Malcolm Tan @ibdgastrodocsg.bsky.social · 12/02/2025Defunctioning stomas are used to treat refractory Crohn's disease - most are permanent (low rates of successful reversal) - some go on to have proctectomy for perianal disease - successful reversal is a/w anti-TNF treatment #IBDSky #SurgSky pubmed.ncbi.nlm.nih.gov/39887905/ 000
Malcolm Tan @ibdgastrodocsg.bsky.social · 30/01/2025Useful article on how to handle IBD medications peri-operatively. - IBD vs non-IBD surgery - biologics vs small molecules - risk of complications - urgency of surgery - post-op IBD treatment plans #GISky #IBDSky #SurgSky www.cghjournal.org/article/S154... @amergastroassn.bsky.social 042
Malcolm Tan @ibdgastrodocsg.bsky.social · 25/01/2025Guidelines for Hepatitis B Virus reactivation - anti-integrin and anti-cytokines classified as "high risk" (>10% HBVr in HBsAg+) - VDZ and UST would be "high risk" --> but VDZ classified as "gut specific anti-T cell rx" --> did not expect UST to be "high risk" #IBDSky #LiverSky 2104
Malcolm Tan @ibdgastrodocsg.bsky.social · 18/01/2025HELIOS trial (neoplasia detection in IBD) - high-def segmental re-inspection is not inferior to high-def chromoendoscopy (10.3% vs 13.1%, non-inferiority margin of 10%) - 'benefit' of chromoendoscopy might be due to withdrawal/inspection time - overall neoplasia rate was low (10.5%) #IBDSky 152
Malcolm Tan @ibdgastrodocsg.bsky.social · 12/01/2025"JAKne" or JAK-inhibitor induced acne - ~5-20% of pts on JAK-inh - absence of comedones, pruritic, widespread (back/chest) - usually manageable with topical treatments (retinoids, topical abx, benzoyl peroxide) #IBDSky #DermSky @amcollegegastro.bsky.social 172
Malcolm Tan @ibdgastrodocsg.bsky.social · 05/01/2025Ulcerative colitis in pts with PSC (compared to UC w/o PSC) - more extensive (pancolitis) - milder disease course - heavier disease burden on right - rectal sparing + ileitis - higher risk of dysplasia and colorectal cancer (annual screening) #IBDSky #LiverSky #GISky @natrevgastrohep.bsky.social 2125
Malcolm Tan @ibdgastrodocsg.bsky.social · 05/01/2025Crohn's disease in pts with PSC (compared to CD w/o PSC). - isolated ileal disease is rare (3-6%) - milder inflammation - lower rates of B2/B3 - ?rectal sparing - ?higher disease burden on the right #IBDSky #LiverSky 0133
Malcolm Tan @ibdgastrodocsg.bsky.social · 28/12/2024Pouch disorders are challenging to manage: - antibiotics still the mainstay rx for acute/chronic pouchitis - budesonide or topical steroids - anti-TNF, vedolizumab for chronic antibiotic-refractory pouchitis or Crohn's-like disease of the pouch #IBDSky @natrevgastrohep.bsky.social 0101
Malcolm Tan @ibdgastrodocsg.bsky.social · 28/12/2024J-pouch anatomy: - appreciating the anatomy & accurate endoscopic reporting is critical in understanding the aetiology of "pouchitis" - different segmental involvement suggest different causes --> different rx approaches #IBDSky @amergastroassn.bsky.social @natrevgastrohep.bsky.social 151
Malcolm Tan @ibdgastrodocsg.bsky.social · 28/12/2024J-pouch inflammation: - can be classified into 7 endoscopic phenotypes - diffuse inflammation, inlet stenosis and cuffitis were associated with pouch excision doi: 10.1016/j.cgh.2021.02.010 #IBDSky @amergastroassn.bsky.social 083
Malcolm Tan @ibdgastrodocsg.bsky.social · 28/12/2024Crohn's disease of the pouch (CDP) - pre-op dx of CD is the largest risk factor - characterised by stenoses, fistulas & pre-pouch ileitis - tends to occur later (>6-12 mths after IPAA) - rx is similar to CD (steroids, immunomodulators, biologics, dilatation, stricturotomy) #IBDSky 110
Malcolm Tan @ibdgastrodocsg.bsky.social · 25/12/2024EXIT trial: Withdrawal of anti-TNF in IBD - 140 well patients randomised to maintenance vs withdrawal - "similar" outcomes at 12 mths: --> clinical remission (84% vs 76%) --> severe endoscopic lesions: (8.5% vs 19%) - calpro >250ug/g at baseline a/w lower rates of clinical remission #IBDSky 183
Malcolm Tan @ibdgastrodocsg.bsky.social · 15/12/2024Functional cure in chronic HBV infection - defined by "off-treatment sustained undetectable HBV DNA and HBsAg" - a/w lowest residual HCC risk Combination of: - short interfering RNA (eg. xalnesiran) + immunomodulator -> TLR7 agonist (eg. ruzotolimod) -> PEGinterferon-α2a #LiverSky #GISky @nejm.org 130
Malcolm Tan @ibdgastrodocsg.bsky.social · 14/12/2024As 2024 draws to an end, several significant publications have advanced our understanding of inflammatory bowel disease treatment. Key studies offer important insights and a few are worth highlighting... ...continue reading at --> substack.com/home/post/p-... #IBDSky #GISkysubstack.comNotable IBD publications in 2024As 2024 draws to an end, several significant publications have advanced our understanding of inflammatory bowel disease (IBD) treatment. 163
Malcolm Tan @ibdgastrodocsg.bsky.social · 14/12/2024Is PSC-IBD a single disease entity? instead of being variants of UC/CD or an EIM? - most PSC pts have gut inflammation - right sided disease, rectal sparing, backwash ileitis - milder activity, more extensive, higher risk of CRC - gut-liver axis #IBDSky #GISky #LiverSky 152
Malcolm Tan @ibdgastrodocsg.bsky.social · 14/12/2024Colonic dysplasia/cancer in PSC-IBD - majority are right-sided - ?younger age of onset - risk starts at dx of PSC, not after 10 years of IBD - a/w poorer outcomes - high rates of invisible dysplasia, multifocality & non-conventional types of dysplasia #IBDSky #GISky #LiverSky 031
Malcolm Tan @ibdgastrodocsg.bsky.social · 14/12/2024PSC-IBD is a/w higher risk of certain cancers: - cholangioCa - gallbladder Ca - colorectal Ca - hepatocellular Ca (if cirrhotic) - ?pancreatic Ca Screening with: - US (+/- MRC, CA 19-9) every 6 -12 mths - annual colonoscopy (high-definition, random biopsies) #IBDSky #GISky #LiverSky 062
Malcolm Tan @ibdgastrodocsg.bsky.social · 14/12/2024Adalimumab in UC. (not a good idea) - inferior to VDZ (22.5% vs 31.3% ClinRem at 52w) - in another study, 22% UC pts remained on ADAL by 54w (c/f 51% for ADAL in CD) - ADAL works great in CD but not in UC --> not sure why, but unlikely to be related to dosing. #IBDSky 121
Malcolm Tan @ibdgastrodocsg.bsky.social · 14/12/2024Complications of H. pylori infection: - peptic ulcers - atrophic gastritis - gastric adenoCa (intestinal type) - MALT lymphoma #GISky 020
Malcolm Tan @ibdgastrodocsg.bsky.social · 14/12/2024Gastric MALT lymphoma: - chronic inflammation by H pylori - polyclonal proliferation of B-cells + inflammation - acquisition of mutations - development of MALT lymphoma - transformation to aggressive DLBCL #GISky #OncoSky #PathSky www.nature.com/articles/nrg... 051
Malcolm Tan @ibdgastrodocsg.bsky.social · 13/12/2024Fibrostenosing Crohn's disease - difficult to manage, native + anastomotic Consensus article: - imaging is required for diagnosis -- narrowing + bowel wall thickness + prestenotic dilatation Treatment options: - anti-TNF, anti-p40 - endoscopic dilatation (<5cm) or surgery #IBDSky #GISky #SurgSky 130
Malcolm Tan @ibdgastrodocsg.bsky.social · 07/12/2024Waste generated by endoscopic procedures 100 endoscopies uses... -- 1385 gallons of water -- 1980 kWh of energy ...and produces... -- 303 kg of solid waste (20% of waste potentially recyclable) -- 1501 kg of CO2e (which requires 1.8 acres of forestry to sequester) #GISky 151
Malcolm Tan @ibdgastrodocsg.bsky.social · 06/12/2024FMT in mild-moderate Crohn's - n=26, Harvey Bradshaw Index: 6-15 - FMT given via colonoscopy + oral capsule - endpoint: clin + endo remission at week 8 Negative study -- no difference between FMT (0/15) vs placebo (1/11) #IBDSky #GISky @amcollegegastro.bsky.social 140
Malcolm Tan @ibdgastrodocsg.bsky.social · 06/12/2024Filgotinib in mod-severe Crohn's (DIVERSITY) - phase 3 RCT, n=1372 - primary endpoints at weeks 10 and 58, clin remission + endo response -- EU vs non-EU groups - negative for induction, mainly due to lack of endoscopic response - positive results for maintenance #IBDSky #GISky 172
Malcolm Tan @ibdgastrodocsg.bsky.social · 01/12/2024Computer aided detection (CADe) in colonoscopy. - CADe improves adenoma detection but mostly <5mm (74%) - greatest improvement seen low ADR endoscopists But: - increased procedure time by 6 mins - additional workload - changed surveillance recommendations in 2.3% (no. of polyps) #MedSky #GISky 160
Malcolm Tan @ibdgastrodocsg.bsky.social · 29/11/2024Tusilokibart (ARTEMIS-UC, phase 2) - anti-TL1A (new class in IBD) - phase 2 but very impressive delta (Week 12 clinical remission of 26% vs 1% in placebo) - no safety signals A potential game changer like IFX or JAK1-inh? Looking forward to phase 3 studies in both CD and UC. #IBDSky #MedSky 260
Malcolm Tan @ibdgastrodocsg.bsky.social · 28/11/2024IFX+AZA vs AZA in ASUC pts who responded to IV steroids (ACTIVE trial) - n=64, bio-naive pts - steroids stopped after d7 (combo arm), d14 (AZA arm) - IFX dose escalation to 10mg/kg allowed - no deaths or colectomy - IFX/AZA had lower rates of "failure" by week 52 Practice changing? #IBDSky #MedSky 161
