# Montreal IBD classification Montreal IBD Status: LIVE Price: $0.005 USDC `GET /api/calc/montreal_ibd` HTML: https://magentlab.com/docs/montreal-ibd Markdown: https://magentlab.com/docs/montreal-ibd.md Not a medical device. Not a diagnosis, dose, or listing recommendation. ## What it computes Apply the Satsangi 2006 Montreal revision of the Vienna IBD classification and return the compact phenotype string for Crohn (age, location, behaviour, optional +L4 and p) or ulcerative colitis (extent and severity). ## When to use When an agent already has caller-assigned Montreal tokens (Crohn A1-A3, L1-L4, B1-B3, upper GI and perianal modifiers, or UC E1-E3 and S0-S3) and needs the published phenotype notation. magent does not perform endoscopy, take vitals, or assign the S token from labs. Not a disease-activity index. ## When not to use - Not a medical device. - Not a diagnosis. magent does not diagnose Crohn disease or ulcerative colitis. - Not a disease-activity index. This tool is phenotype notation only, not CDAI, Harvey-Bradshaw, or Mayo DAI. - Not the Paris pediatric classification. - IBDU and indeterminate colitis are not encoded; disease must be crohn or uc. - The caller assigns all tokens, including UC severity S0-S3. magent does not perform endoscopy or take vitals. ## Formula ``` Crohn phenotype = age_at_diagnosis (A1 ≤16 y, A2 17-40 y, A3 >40 y) + location (L1 ileal, L2 colonic, L3 ileocolonic, L4 isolated upper GI) + optional +L4 when concomitant upper GI with L1-L3 (forbidden when location is isolated L4) + behaviour (B1 non-stricturing non-penetrating, B2 stricturing, B3 penetrating) + optional p when concomitant perianal disease; UC phenotype = extent (E1 ulcerative proctitis distal to the rectosigmoid junction, E2 left-sided distal to the splenic flexure, E3 extensive proximal to the splenic flexure) + severity (S0 clinical remission, S1 mild, S2 moderate, S3 severe as assigned) (Satsangi 2006 Montreal revision of Vienna). Compact string, no spaces. Not a disease-activity score. magent does not perform endoscopy. Not Paris pediatric classification. ``` ## Citation [The Montreal classification of inflammatory bowel disease: controversies, consensus, and implications](https://doi.org/10.1136/gut.2005.082909) Satsangi J, Silverberg MS, Vermeire S, Colombel JF Gut. 2006;55(6):749-753 DOI: [10.1136/gut.2005.082909](https://doi.org/10.1136/gut.2005.082909) ## Worked example ### Crohn A2 ileocolonic non-stricturing non-penetrating Given: `age_at_diagnosis=A2, behaviour=B1, disease=crohn, location=L3, perianal=false, upper_gi=false` 1. disease crohn 2. age_at_diagnosis A2 (17-40 y) 3. location L3 ileocolonic 4. upper_gi false (no +L4) 5. behaviour B1 non-stricturing non-penetrating 6. perianal false (no p) 7. phenotype A2L3B1 ### UC ulcerative proctitis in clinical remission Given: `disease=uc, extent=E1, severity=S0` 1. disease uc 2. extent E1 ulcerative proctitis 3. severity S0 clinical remission as assigned 4. phenotype E1S0 ## Also searched as - Montreal classification - Montreal IBD - Satsangi 2006 - Crohn phenotype A L B - ulcerative colitis extent E1 E2 E3 - Montreal UC severity - Vienna Montreal revision - IBD phenotype notation - Montreal L4 p modifier ## Parameters - `disease` (string, required): Satsangi 2006 Montreal disease as assigned: crohn or uc. IBDU and indeterminate colitis are not encoded. magent does not diagnose IBD. - `age_at_diagnosis` (string, optional): Montreal Crohn age at diagnosis as assigned (Satsangi 2006): A1 ≤16 years, A2 17-40 years, A3 >40 years. Required when disease=crohn. Omit when disease=uc. magent does not assign the A token from a chart. - `location` (string, optional): Montreal Crohn location as assigned (Satsangi 2006): L1 ileal, L2 colonic, L3 ileocolonic, L4 isolated upper GI. Required when disease=crohn. Omit when disease=uc. magent does not perform endoscopy. - `upper_gi` (boolean, optional): Concomitant upper GI disease as assigned (Satsangi 2006 L4 modifier). true adds +L4 after L1, L2, or L3. Must be false when location is isolated L4. Required when disease=crohn. Omit when disease=uc. magent does not perform endoscopy. - `behaviour` (string, optional): Montreal Crohn behaviour as assigned (Satsangi 2006): B1 non-stricturing non-penetrating, B2 stricturing, B3 penetrating. Required when disease=crohn. Omit when disease=uc. magent does not perform endoscopy. - `perianal` (boolean, optional): Concomitant perianal disease as assigned (Satsangi 2006 p modifier). true appends p after B1, B2, or B3. Required when disease=crohn. Omit when disease=uc. magent does not examine the patient. - `extent` (string, optional): Montreal UC extent as assigned (Satsangi 2006): E1 ulcerative proctitis (distal to the rectosigmoid junction), E2 left-sided (distal to the splenic flexure), E3 extensive (proximal to the splenic flexure). Required when disease=uc. Omit when disease=crohn. magent does not perform endoscopy. - `severity` (string, optional): Montreal UC severity as assigned (Satsangi 2006): S0 clinical remission; S1 mild (≤4 stools/day with or without blood, no systemic illness, normal ESR); S2 moderate (>4 stools/day, minimal systemic toxicity); S3 severe (≥6 bloody stools/day AND pulse ≥90 AND temperature ≥37.5°C AND haemoglobin <10.5 g/100 ml AND ESR ≥30 mm/h). The caller assigns the S token. Required when disease=uc. Omit when disease=crohn. magent does not take vitals. ## Bulk (POST) POST the same path with a JSON items array. The first item is the GET unit; each additional item is $0.002. Invalid items return HTTP 400 before settlement. Method: `POST /api/calc/montreal_ibd` Max items: 25 Price: unit_amount + extra_item_amount * (n - 1) (unit 5000 atomic, extra 2000 atomic) Status: PREVIEW - 1 to 25 items. Each item uses the same keys as the GET query parameters. - POST of 1 item costs the same as GET. Lists longer than 25: chunk into multiple POSTs. Extra items still execute; do not pad dummy rows. - The first invalid item fails the whole request (index in the 400 JSON). You are not charged. - HTTP 200 is {count, path, items}. Each items[i] is the GET 200 body for that row. - Catalog misses (empty matches, found=false) stay paid 200s inside that slot. - x402 resource URL is this path plus n and body_sha256. Browsers that prefer text/html get the same paywall as GET; Pay retries POST with the same items. Example request: ```json { "items": [ { "age_at_diagnosis": "A2", "behaviour": "B1", "disease": "crohn", "location": "L3", "perianal": "false", "upper_gi": "false" }, { "age_at_diagnosis": "A2", "behaviour": "B1", "disease": "crohn", "location": "L3", "perianal": "false", "upper_gi": "false" } ] } ``` Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/montreal-ibd Example 200: ```json { "count": 2, "path": "/api/calc/montreal_ibd", "items": [ { "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.", "citation": { "authors": "Satsangi J, Silverberg MS, Vermeire S, Colombel JF", "doi": "10.1136/gut.2005.082909", "id": "satsangi-2006", "pmid": "16698746", "source": "Gut. 2006;55(6):749-753", "title": "The Montreal classification of inflammatory bowel disease: controversies, consensus, and implications" }, "formula": "montreal_ibd", "formula_expression": "Crohn phenotype = age_at_diagnosis (A1 ≤16 y, A2 17-40 y, A3 >40 y) + location (L1 ileal, L2 colonic, L3 ileocolonic, L4 isolated upper GI) + optional +L4 when concomitant upper GI with L1-L3 (forbidden when location is isolated L4) + behaviour (B1 non-stricturing non-penetrating, B2 stricturing, B3 penetrating) + optional p when concomitant perianal disease; UC phenotype = extent (E1 ulcerative proctitis distal to the rectosigmoid junction, E2 left-sided distal to the splenic flexure, E3 extensive proximal to the splenic flexure) + severity (S0 clinical remission, S1 mild, S2 moderate, S3 severe as assigned) (Satsangi 2006 Montreal revision of Vienna). Compact string, no spaces. Not a disease-activity score. magent does not perform endoscopy. Not Paris pediatric classification.", "criteria": [ { "factor": "disease_crohn", "met": true }, { "factor": "disease_uc", "met": false }, { "factor": "A1", "met": false }, { "factor": "A2", "met": true }, { "factor": "A3", "met": false }, { "factor": "L1", "met": false }, { "factor": "L2", "met": false }, { "factor": "L3", "met": true }, { "factor": "L4", "met": false }, { "factor": "upper_gi", "met": false }, { "factor": "B1", "met": true }, { "factor": "B2", "met": false }, { "factor": "B3", "met": false }, { "factor": "perianal", "met": false } ], "phenotype": "A2L3B1", "disease": "crohn" }, { "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.", "citation": { "authors": "Satsangi J, Silverberg MS, Vermeire S, Colombel JF", "doi": "10.1136/gut.2005.082909", "id": "satsangi-2006", "pmid": "16698746", "source": "Gut. 2006;55(6):749-753", "title": "The Montreal classification of inflammatory bowel disease: controversies, consensus, and implications" }, "formula": "montreal_ibd", "formula_expression": "Crohn phenotype = age_at_diagnosis (A1 ≤16 y, A2 17-40 y, A3 >40 y) + location (L1 ileal, L2 colonic, L3 ileocolonic, L4 isolated upper GI) + optional +L4 when concomitant upper GI with L1-L3 (forbidden when location is isolated L4) + behaviour (B1 non-stricturing non-penetrating, B2 stricturing, B3 penetrating) + optional p when concomitant perianal disease; UC phenotype = extent (E1 ulcerative proctitis distal to the rectosigmoid junction, E2 left-sided distal to the splenic flexure, E3 extensive proximal to the splenic flexure) + severity (S0 clinical remission, S1 mild, S2 moderate, S3 severe as assigned) (Satsangi 2006 Montreal revision of Vienna). Compact string, no spaces. Not a disease-activity score. magent does not perform endoscopy. Not Paris pediatric classification.", "criteria": [ { "factor": "disease_crohn", "met": true }, { "factor": "disease_uc", "met": false }, { "factor": "A1", "met": false }, { "factor": "A2", "met": true }, { "factor": "A3", "met": false }, { "factor": "L1", "met": false }, { "factor": "L2", "met": false }, { "factor": "L3", "met": true }, { "factor": "L4", "met": false }, { "factor": "upper_gi", "met": false }, { "factor": "B1", "met": true }, { "factor": "B2", "met": false }, { "factor": "B3", "met": false }, { "factor": "perianal", "met": false } ], "phenotype": "A2L3B1", "disease": "crohn" } ] } ``` ## Response fields - `formula` (string): montreal_ibd - `formula_expression` (string): Published Satsangi 2006 Montreal phenotype notation - `disease` (string): crohn or uc as assigned. IBDU is not encoded. - `phenotype` (string): Compact Montreal phenotype with no spaces. Crohn examples: A2L3B1, A2L3+L4B1, A2L3B1p, A1L4B2, A3L1+L4B3p. UC examples: E1S0, E2S1, E3S3. Not a disease-activity score. - `criteria` (array): Tree rows with factor and met for disease plus the exclusive Montreal tokens and Crohn modifiers used on that request - `citation` (object): Satsangi 2006 Gut citation - `disclaimer` (string): Not-a-device notice ## Example JSON Frozen fixture. Not a live lookup. ```json { "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.", "citation": { "authors": "Satsangi J, Silverberg MS, Vermeire S, Colombel JF", "doi": "10.1136/gut.2005.082909", "id": "satsangi-2006", "pmid": "16698746", "source": "Gut. 2006;55(6):749-753", "title": "The Montreal classification of inflammatory bowel disease: controversies, consensus, and implications" }, "formula": "montreal_ibd", "formula_expression": "Crohn phenotype = age_at_diagnosis (A1 ≤16 y, A2 17-40 y, A3 >40 y) + location (L1 ileal, L2 colonic, L3 ileocolonic, L4 isolated upper GI) + optional +L4 when concomitant upper GI with L1-L3 (forbidden when location is isolated L4) + behaviour (B1 non-stricturing non-penetrating, B2 stricturing, B3 penetrating) + optional p when concomitant perianal disease; UC phenotype = extent (E1 ulcerative proctitis distal to the rectosigmoid junction, E2 left-sided distal to the splenic flexure, E3 extensive proximal to the splenic flexure) + severity (S0 clinical remission, S1 mild, S2 moderate, S3 severe as assigned) (Satsangi 2006 Montreal revision of Vienna). Compact string, no spaces. Not a disease-activity score. magent does not perform endoscopy. Not Paris pediatric classification.", "criteria": [ { "factor": "disease_crohn", "met": true }, { "factor": "disease_uc", "met": false }, { "factor": "A1", "met": false }, { "factor": "A2", "met": true }, { "factor": "A3", "met": false }, { "factor": "L1", "met": false }, { "factor": "L2", "met": false }, { "factor": "L3", "met": true }, { "factor": "L4", "met": false }, { "factor": "upper_gi", "met": false }, { "factor": "B1", "met": true }, { "factor": "B2", "met": false }, { "factor": "B3", "met": false }, { "factor": "perianal", "met": false } ], "phenotype": "A2L3B1", "disease": "crohn" } ``` ## Errors - HTTP 400 `invalid_montreal_ibd`: Montreal IBD needs disease crohn or uc with the Satsangi 2006 phenotype tokens. Returned before settlement; you are not charged. - HTTP 400 `invalid_items`: POST body must be a JSON object with only an items array Returned before settlement; you are not charged. - HTTP 400 `invalid_item_count`: items must be an array of 1 to 25 objects Returned before settlement; you are not charged. - HTTP 400 `invalid_item`: each items entry must be a JSON object Returned before settlement; you are not charged. Shared HTTP 402 and 503: https://magentlab.com/docs/payments ## Related tools - [Mayo DAI](https://magentlab.com/docs/mayo-uc) — Sum four caller-assigned Schroeder 1987 ulcerative colitis disease-activity index items (each integer 0-3) and return the total (max 12). Does not return later remission or activity bands. - [HBI](https://magentlab.com/docs/harvey-bradshaw) — Sum Harvey 1980 simple-index items (previous-day well-being, abdominal pain, liquid stools, abdominal mass, and one point per listed complication) and return the total. Does not return later remission or activity bands. - [CDAI](https://magentlab.com/docs/cdai) — Compute the Best 1976 Crohn's disease activity index from eight caller-assigned variables and return the rounded integer score. Does not return later trial activity bands. ## Payment Unpaid requests return HTTP 402 even if query parameters or POST items are missing or invalid, so CDP and agents can index the path. After a PAYMENT-SIGNATURE, invalid params return HTTP 400 JSON before settlement. magent does not charge. Fix the params, then request a new 402 quote for that complete URL. Catalog misses (empty matches, found=false) are valid paid 200s. - GET the tool with Accept: application/json (do not send Accept: text/html unless you want the human paywall). - HTTP 402 means you have not paid. Decode the base64 PAYMENT-REQUIRED header. HTTP 503 is not a new quote. - Sign accepts[0] (exact, EIP-3009) with validBefore = now + maxTimeoutSeconds (600 seconds), or accepts[1] (batch-settlement deposit/voucher) on product GET. Ping and POST {items} stay exact. Magent retries transient facilitator 429/5xx before answering. - Retry the same URL with PAYMENT-SIGNATURE (base64 JSON of accepted and payload). Magent attaches canonical extensions.bazaar on CDP verify/settle; echoing 402 bazaar is optional. - Success is HTTP 200 JSON plus PAYMENT-RESPONSE. exact settles before the tool. batch-settlement verifies (and deposit-settles) before the tool and commits the charge after HTTP 2xx. HTTP 503: retry the same PAYMENT-SIGNATURE. Mint a new exact nonce only after a new HTTP 402. - offered `exact` on eip155:8453: Fixed-price USDC on Base. The buyer authorizes the advertised amount (EIP-3009). magent settles before the tool runs (paymentFlow upfront). extra.assetTransferMethod=eip3009 extra.paymentFlow=upfront. - offered `batch-settlement` on eip155:8453: Payment-channel vouchers claimed later in batches. Exact stays accepts[0]. Same-path POST {items} is still exact. extra.assetTransferMethod=eip3009 extra.paymentFlow=authorization. - not offered `upto`: Not offered. Usage-based: buyer authorizes a ceiling, seller settles the actual amount after work. Reserved for a future metered tool. Not for current calculators or code search. Same-path POST {items} is still scheme exact: one EIP-3009 authorization for GET unit plus $0.002 per extra item. That is not x402 batch-settlement (payment channels / vouchers). Shared HTTP 402 and 503 table: https://magentlab.com/docs/payments Stdio MCP (one process per host): https://magentlab.com/docs/mcp ## Guarantees - HTTP 402 is unpaid, including a missing query. After PAYMENT-SIGNATURE, invalid parameters return HTTP 400 before settlement. You are not charged. HTTP 402 never includes the tool JSON. - exact: settlement finishes before the tool (paymentFlow upfront). batch-settlement: verify/deposit before the tool; chargedCumulativeAmount commits after HTTP 2xx. Uncertain or failed settlement fails closed (HTTP 503). Retry the same PAYMENT-SIGNATURE. - HTTP 402 is unpaid only. Do not sign a second authorization because of a 503. - Execution is timeout-bounded and concurrency-capped. - Calculator inputs are stored encrypted for allowlisted operators (Magent Console). They are not in public logs, SSH lookups, catalog, or rollups. Request logs store path without query.