# Rome III IBS criteria

Rome III IBS

Status: LIVE
Price: $0.005 USDC
`GET /api/calc/rome_iii_ibs`
HTML: https://magentlab.com/docs/rome-iii-ibs
Markdown: https://magentlab.com/docs/rome-iii-ibs.md

Not a medical device. Not a diagnosis, dose, or listing recommendation.

## What it computes

Apply the Longstreth 2006 Rome III IBS diagnostic criteria and return supporting_features_met (0-3) and whether the published IBS box holds (rome_iii_ibs).

## When to use

When an agent already has the five caller-assigned Rome III IBS flags as in Longstreth 2006 and needs whether the published IBS box holds. magent does not examine the patient.

## When not to use

- Not a medical device.
- Not a diagnosis. magent does not diagnose irritable bowel syndrome.
- The caller assigns the five flags. magent does not examine the patient.
- This tool is the Longstreth 2006 Rome III IBS diagnostic box only. Not Rome IV (pain at least 1 day per week), not Manning criteria, and not IBS-C/D/M subtype.

## Formula

```
rome_iii_ibs iff pain_or_discomfort_3_days_per_month_last_3_months and symptom_onset_at_least_6_months_prior and supporting_features_met >= 2; supporting_features_met counts improvement_with_defecation, onset_change_stool_frequency, and onset_change_stool_form (Longstreth 2006 Rome III IBS diagnostic criteria)
```

## Citation

[Functional bowel disorders](https://doi.org/10.1053/j.gastro.2005.11.061)
Longstreth GF, Thompson WG, Chey WD, Houghton LA, Mearin F, Spiller RC
Gastroenterology. 2006;130(5):1480-1491
DOI: [10.1053/j.gastro.2005.11.061](https://doi.org/10.1053/j.gastro.2005.11.061)

## Worked example

### Pain, 6-month onset, and two supporting features

Given: `improvement_with_defecation=true, onset_change_stool_form=false, onset_change_stool_frequency=true, pain_or_discomfort_3_days_per_month_last_3_months=true, symptom_onset_at_least_6_months_prior=true`

1. Pain or discomfort at least 3 days per month in the last 3 months is true
2. Symptom onset at least 6 months prior is true
3. Improvement with defecation and change in stool frequency are true; change in stool form is false (2 of 3)
4. rome_iii_ibs is true


### Pain and 6-month onset with only one supporting feature

Given: `improvement_with_defecation=true, onset_change_stool_form=false, onset_change_stool_frequency=false, pain_or_discomfort_3_days_per_month_last_3_months=true, symptom_onset_at_least_6_months_prior=true`

1. Pain and 6-month onset hold
2. Only improvement with defecation is true (1 of 3)
3. rome_iii_ibs is false


## Also searched as

- Rome III IBS
- Rome III irritable bowel
- Longstreth IBS criteria
- functional bowel IBS 2006
- IBS diagnostic criteria Rome III
- Longstreth 2006 IBS
- irritable bowel syndrome Rome III
- Rome III IBS box

## Parameters

- `pain_or_discomfort_3_days_per_month_last_3_months` (boolean, required): Recurrent abdominal pain or discomfort at least 3 days per month in the last 3 months (Longstreth 2006). true or false as assigned by the caller. magent does not examine the patient.
- `symptom_onset_at_least_6_months_prior` (boolean, required): Symptom onset at least 6 months prior to diagnosis, as assigned (Longstreth 2006). true or false as assigned by the caller. magent does not take a history.
- `improvement_with_defecation` (boolean, required): Improvement with defecation (one of three supporting features; at least two required). true or false as assigned by the caller.
- `onset_change_stool_frequency` (boolean, required): Onset associated with a change in frequency of stool (one of three supporting features; at least two required). true or false as assigned by the caller.
- `onset_change_stool_form` (boolean, required): Onset associated with a change in form (appearance) of stool (one of three supporting features; at least two required). true or false as assigned by the caller.

## 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/rome_iii_ibs`
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": [
    {
      "improvement_with_defecation": "true",
      "onset_change_stool_form": "false",
      "onset_change_stool_frequency": "true",
      "pain_or_discomfort_3_days_per_month_last_3_months": "true",
      "symptom_onset_at_least_6_months_prior": "true"
    },
    {
      "improvement_with_defecation": "true",
      "onset_change_stool_form": "false",
      "onset_change_stool_frequency": "true",
      "pain_or_discomfort_3_days_per_month_last_3_months": "true",
      "symptom_onset_at_least_6_months_prior": "true"
    }
  ]
}
```

Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/rome-iii-ibs

Example 200:

```json
{
  "count": 2,
  "path": "/api/calc/rome_iii_ibs",
  "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": "Longstreth GF, Thompson WG, Chey WD, Houghton LA, Mearin F, Spiller RC",
        "doi": "10.1053/j.gastro.2005.11.061",
        "id": "longstreth-2006",
        "pmid": "16678561",
        "source": "Gastroenterology. 2006;130(5):1480-1491",
        "title": "Functional bowel disorders"
      },
      "formula": "rome_iii_ibs",
      "formula_expression": "rome_iii_ibs iff pain_or_discomfort_3_days_per_month_last_3_months and symptom_onset_at_least_6_months_prior and supporting_features_met >= 2; supporting_features_met counts improvement_with_defecation, onset_change_stool_frequency, and onset_change_stool_form (Longstreth 2006 Rome III IBS diagnostic criteria)",
      "criteria": [
        {
          "factor": "pain_or_discomfort_3_days_per_month_last_3_months",
          "met": true
        },
        {
          "factor": "symptom_onset_at_least_6_months_prior",
          "met": true
        },
        {
          "factor": "improvement_with_defecation",
          "met": true
        },
        {
          "factor": "onset_change_stool_frequency",
          "met": true
        },
        {
          "factor": "onset_change_stool_form",
          "met": false
        },
        {
          "value": 2,
          "factor": "supporting_features_ge_2",
          "met": true
        }
      ],
      "rome_iii_ibs": true,
      "supporting_features_met": 2
    },
    {
      "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": "Longstreth GF, Thompson WG, Chey WD, Houghton LA, Mearin F, Spiller RC",
        "doi": "10.1053/j.gastro.2005.11.061",
        "id": "longstreth-2006",
        "pmid": "16678561",
        "source": "Gastroenterology. 2006;130(5):1480-1491",
        "title": "Functional bowel disorders"
      },
      "formula": "rome_iii_ibs",
      "formula_expression": "rome_iii_ibs iff pain_or_discomfort_3_days_per_month_last_3_months and symptom_onset_at_least_6_months_prior and supporting_features_met >= 2; supporting_features_met counts improvement_with_defecation, onset_change_stool_frequency, and onset_change_stool_form (Longstreth 2006 Rome III IBS diagnostic criteria)",
      "criteria": [
        {
          "factor": "pain_or_discomfort_3_days_per_month_last_3_months",
          "met": true
        },
        {
          "factor": "symptom_onset_at_least_6_months_prior",
          "met": true
        },
        {
          "factor": "improvement_with_defecation",
          "met": true
        },
        {
          "factor": "onset_change_stool_frequency",
          "met": true
        },
        {
          "factor": "onset_change_stool_form",
          "met": false
        },
        {
          "value": 2,
          "factor": "supporting_features_ge_2",
          "met": true
        }
      ],
      "rome_iii_ibs": true,
      "supporting_features_met": 2
    }
  ]
}
```

## Response fields

- `formula` (string): rome_iii_ibs
- `formula_expression` (string): Longstreth 2006 Rome III IBS box: pain/discomfort 3 days/month for 3 months, onset 6 months, and at least 2 of 3 supporting features
- `supporting_features_met` (integer): Count of true supporting features among improvement with defecation, change in stool frequency, and change in stool form (0-3)
- `rome_iii_ibs` (boolean): true only when pain/discomfort, 6-month onset, and at least two supporting features all hold. Not a diagnosis.
- `criteria` (array): Per-factor rows with factor and met; supporting_features_ge_2 includes value 0-3
- `citation` (object): Longstreth 2006 Gastroenterology 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": "Longstreth GF, Thompson WG, Chey WD, Houghton LA, Mearin F, Spiller RC",
    "doi": "10.1053/j.gastro.2005.11.061",
    "id": "longstreth-2006",
    "pmid": "16678561",
    "source": "Gastroenterology. 2006;130(5):1480-1491",
    "title": "Functional bowel disorders"
  },
  "formula": "rome_iii_ibs",
  "formula_expression": "rome_iii_ibs iff pain_or_discomfort_3_days_per_month_last_3_months and symptom_onset_at_least_6_months_prior and supporting_features_met >= 2; supporting_features_met counts improvement_with_defecation, onset_change_stool_frequency, and onset_change_stool_form (Longstreth 2006 Rome III IBS diagnostic criteria)",
  "criteria": [
    {
      "factor": "pain_or_discomfort_3_days_per_month_last_3_months",
      "met": true
    },
    {
      "factor": "symptom_onset_at_least_6_months_prior",
      "met": true
    },
    {
      "factor": "improvement_with_defecation",
      "met": true
    },
    {
      "factor": "onset_change_stool_frequency",
      "met": true
    },
    {
      "factor": "onset_change_stool_form",
      "met": false
    },
    {
      "value": 2,
      "factor": "supporting_features_ge_2",
      "met": true
    }
  ],
  "rome_iii_ibs": true,
  "supporting_features_met": 2
}
```

## Errors

- HTTP 400 `invalid_flag`: boolean clinical flags must be true or false 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

- [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.
- [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.

## 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.