Clinical decision support

Clinical decision support

Decision support tools

Guideline-anchored tools that show which published recommendations apply to a given clinical situation. Every recommendation is quoted verbatim from the cited guideline and machine-verified against its full text. These tools surface the evidence, they do not predict outcomes or replace clinical judgment.

Surgery or Keep Trying Medication? Ileocecal Crohn's, Side by SideNew tool

For limited Crohn's at the end of the small bowel that isn't responding to medication, weigh an operation against a biologic, side by side, grounded in the LIR!C trial.

Open the tool →
Guidelines & calculators

Practice guidelines and risk calculators

Third-party guidelines and prediction tools relevant to Crohn’s disease, each independently verified against PubMed. These are external documents and tools, linked, not reproduced, and not evidence-gated by this site.

Read the access and validation labels. Very few published IBD prediction tools are simultaneously a live free calculator, externally validated, and validated for the decision you are about to make. Where a tool is formula-only, or was validated only in its derivation cohort, that is stated rather than hidden behind a link. 3 further item(s) found by this review are withheld pending clinician sign-off rather than published unverified.

Practice guidelines

Risk calculators and prediction tools

  • Vedolizumab Clinical Decision Support Tool (VDZ-CDST) for Crohn's disease formula only, no calculatorexternally validatedStratifies an individual's probability of clinical / corticosteroid-free remission at ~week 26 on vedolizumab into low, intermediate or high, to inform whether vedolizumab is a sensible choice for that patient · PMID 29857091 Note: Derived in GEMINI 2 and validated in the independent VICTORY practice cohort (n=366), with further external support across GEMINI/GETAID/VICTORY (PMID 31867766), but discrimination is only modest (AUC ~0.68 for week-14 remission in GETAID) and a 2026 real-world cohort (PMID 42075594) found materially different performance in CD vs UC. There is no official free web calculator: the point score has to be applied by hand from the paper. It predicts response to ONE drug and does not rank vedolizumab against alternatives. Note that the AGA 2025 living guideline now places vedolizumab in a lower-efficacy tier for CD, so a 'high probability' CDST result is not by itself an argument for choosing it.
  • ACS NSQIP Surgical Risk Calculator (v4.0.4) live calculatorexternally validatedPredicts 30-day postoperative risk (death, serious complication, SSI, readmission, discharge to nursing facility, etc.) for a planned procedure by CPT code, preoperative counselling and prehabilitation triage before ileocolic resection, redo resection or proctocolectomy Note: Generic, NOT Crohn's-specific. Built on all-comers NSQIP data; it captures steroid use and weight loss but not the CD-specific drivers a surgeon actually weighs, biologic/small-molecule exposure, penetrating phenotype, intra-abdominal abscess or fistula, sarcopenia, reoperative pelvis, number of prior resections. External studies have reported miscalibration in colorectal and IBD subgroups, generally under-predicting risk in the sickest patients. Parameters were last refreshed April 2026 and the version increments, so re-check before quoting an absolute percentage to a patient.
  • Harvey-Bradshaw Index (HBI) live calculatorexternally validatedSingle-day simplified symptomatic activity score used as the practical bedside substitute for CDAI (commonly: <5 remission, 5-7 mild, 8-16 moderate, >16 severe) · PMID 20096379 Note: A SYMPTOM score, not a risk model and not a measure of inflammation, and it was validated against the CDAI (itself a symptom index; Spearman rho 0.80 across ~1,000 paired observations from PRECiSE 1/2, PMID 20096379), NOT against endoscopy or hard outcomes. Remission cut-points differ between publications (<4 vs <5), so state which is in use. Never present a low HBI as evidence of controlled disease without an objective marker alongside it (per STRIDE-II and the AGA biomarker guideline). derivation_pmid given is the CDAI-correlation validation paper; the original Harvey & Bradshaw 1980 Lancet PMID was not verified and is therefore not asserted.

Also on MDCalc

These are established instruments already hosted as free, working calculators by MDCalc. We link them rather than rebuild them. Our own decision-support tools above cover what MDCalc does not, and every link below was verified against MDCalc directly.

  • Montreal Classification for IBD live calculatorclassificationAssigns Montreal extent (E1-E3) and severity (S0-S3) for UC, and age / location / behaviour (A, L, B) for Crohn's. Note: A PHENOTYPE classification, not a prediction model. Extent should be recorded as the maximum ever documented, not the most recent endoscopic appearance, which underestimates true extent in quiescent disease.
  • Crohn's Disease Activity Index (CDAI) live calculatoractivity indexThe historical primary endpoint in Crohn's trials; requires a 7-day patient diary plus labs. Note: Correlates POORLY with endoscopic inflammation. A normal CDAI does not exclude active disease. Explicitly invalid in stricturing/fistulising disease, after extensive resection, and in patients with a stoma. Pair with CRP/faecal calprotectin and imaging.
  • Simplified Endoscopic Activity Score for Crohn's Disease (SES-CD) live calculatorendoscopicEndoscopic activity in Crohn's: ulcer size, ulcerated and affected surface, and stenosis across five segments. Note: Requires full ileocolonoscopy with all five segments assessed; a partial exam is not scoreable. Objective counterpart to the symptom-based CDAI/HBI.

Guideline summaries hosted by MDCalc: