# Rome IV H2a child functional dyspepsia

Rome IV child dyspepsia

Status: LIVE
Price: $0.005 USDC
`GET /api/calc/rome_iv_child_dyspepsia`
HTML: https://magentlab.com/docs/rome-iv-child-dyspepsia
Markdown: https://magentlab.com/docs/rome-iv-child-dyspepsia.md

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

## What it computes

Apply the Hyams 2016 Rome IV H2a child/adolescent functional dyspepsia diagnostic criteria and return symptoms_met (0-3) and whether the published H2a box holds (rome_iv_child_dyspepsia).

## When to use

When an agent already has the caller-assigned Hyams 2016 Rome IV H2a flags (bothersome at least 4 days per month, the three symptoms, exclusion, and 2-month duration) and needs whether the published child functional dyspepsia box holds. magent does not examine the child or parse EGD.

## When not to use

- Not a medical device.
- Not a diagnosis. magent does not diagnose child functional dyspepsia.
- The caller assigns the six flags. magent does not examine the child and does not parse EGD.
- H2a item 4 in the paper box is the exclusion (not_explained_by_another_condition), not a fourth symptom.
- PDS and EPS subtype supportive features in Hyams 2016 H2a (postprandial distress vs epigastric pain syndrome, including bloating, nausea, or belching) are copy-only and are not parsed flags.
- This tool is Hyams 2016 Rome IV H2a child/adolescent functional dyspepsia only. Not adult Rome IV FD (Stanghellini 2016 B1).

## Formula

```
rome_iv_child_dyspepsia iff bothersome_at_least_4_days_per_month and symptoms_met >= 1 and not_explained_by_another_condition and fulfilled_at_least_2_months; symptoms_met counts postprandial_fullness, early_satiation, and epigastric_pain_or_burning_not_associated_with_defecation; H2a item 4 is the exclusion not_explained_by_another_condition, not a fourth symptom; PDS and EPS subtype supportive features are copy-only and are not parsed (Hyams 2016 Rome IV H2a Functional Dyspepsia)
```

## Citation

[Childhood Functional Gastrointestinal Disorders: Child/Adolescent](https://doi.org/10.1053/j.gastro.2016.02.015)
Hyams JS, Di Lorenzo C, Saps M, Shulman RJ, Staiano A, van Tilburg M
Gastroenterology. 2016;150(6):1456-1468
DOI: [10.1053/j.gastro.2016.02.015](https://doi.org/10.1053/j.gastro.2016.02.015)

## Worked example

### Bothersome 4 days, one symptom, exclusion, and 2 months

Given: `bothersome_at_least_4_days_per_month=true, early_satiation=false, epigastric_pain_or_burning_not_associated_with_defecation=false, fulfilled_at_least_2_months=true, not_explained_by_another_condition=true, postprandial_fullness=true`

1. Bothersome at least 4 days per month is true
2. Postprandial fullness is true; early satiation and epigastric pain or burning not associated with defecation are false (symptoms_met 1)
3. Not explained by another condition is true
4. Fulfilled at least 2 months is true
5. rome_iv_child_dyspepsia is true


### Worked example without 2-month duration

Given: `bothersome_at_least_4_days_per_month=true, early_satiation=false, epigastric_pain_or_burning_not_associated_with_defecation=false, fulfilled_at_least_2_months=false, not_explained_by_another_condition=true, postprandial_fullness=true`

1. Bothersome at least 4 days per month, one H2a symptom, and the exclusion hold
2. Fulfilled at least 2 months is false
3. rome_iv_child_dyspepsia is false


## Also searched as

- Rome IV child dyspepsia
- Hyams 2016 functional dyspepsia
- Rome IV H2a
- child functional dyspepsia
- pediatric functional dyspepsia
- Hyams H2a dyspepsia
- postprandial fullness child
- early satiation child
- Rome IV child FD

## Parameters

- `bothersome_at_least_4_days_per_month` (boolean, required): Bothersome symptoms at least 4 days per month, as assigned (Hyams 2016 Rome IV H2a). true or false as assigned by the caller. magent does not examine the child.
- `postprandial_fullness` (boolean, required): Postprandial fullness (one of three H2a symptoms; at least one required). true or false as assigned by the caller. magent does not examine the child.
- `early_satiation` (boolean, required): Early satiation (one of three H2a symptoms; at least one required). true or false as assigned by the caller. magent does not examine the child.
- `epigastric_pain_or_burning_not_associated_with_defecation` (boolean, required): Epigastric pain or burning not associated with defecation (one of three H2a symptoms; at least one required). true or false as assigned by the caller. magent does not examine the child.
- `not_explained_by_another_condition` (boolean, required): After appropriate evaluation, the symptoms cannot be fully explained by another medical condition, as assigned (Hyams 2016 Rome IV H2a item 4, the exclusion, not a fourth symptom). true or false as assigned by the caller. magent does not examine the child or parse EGD.
- `fulfilled_at_least_2_months` (boolean, required): Criteria fulfilled for at least 2 months prior to diagnosis, as assigned (Hyams 2016 Rome IV H2a). true or false as assigned by the caller. magent does not take a history.

## 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_iv_child_dyspepsia`
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": [
    {
      "bothersome_at_least_4_days_per_month": "true",
      "early_satiation": "false",
      "epigastric_pain_or_burning_not_associated_with_defecation": "false",
      "fulfilled_at_least_2_months": "true",
      "not_explained_by_another_condition": "true",
      "postprandial_fullness": "true"
    },
    {
      "bothersome_at_least_4_days_per_month": "true",
      "early_satiation": "false",
      "epigastric_pain_or_burning_not_associated_with_defecation": "false",
      "fulfilled_at_least_2_months": "true",
      "not_explained_by_another_condition": "true",
      "postprandial_fullness": "true"
    }
  ]
}
```

Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/rome-iv-child-dyspepsia

Example 200:

```json
{
  "count": 2,
  "path": "/api/calc/rome_iv_child_dyspepsia",
  "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": "Hyams JS, Di Lorenzo C, Saps M, Shulman RJ, Staiano A, van Tilburg M",
        "doi": "10.1053/j.gastro.2016.02.015",
        "id": "hyams-2016",
        "pmid": "27144632",
        "source": "Gastroenterology. 2016;150(6):1456-1468",
        "title": "Childhood Functional Gastrointestinal Disorders: Child/Adolescent"
      },
      "formula": "rome_iv_child_dyspepsia",
      "formula_expression": "rome_iv_child_dyspepsia iff bothersome_at_least_4_days_per_month and symptoms_met >= 1 and not_explained_by_another_condition and fulfilled_at_least_2_months; symptoms_met counts postprandial_fullness, early_satiation, and epigastric_pain_or_burning_not_associated_with_defecation; H2a item 4 is the exclusion not_explained_by_another_condition, not a fourth symptom; PDS and EPS subtype supportive features are copy-only and are not parsed (Hyams 2016 Rome IV H2a Functional Dyspepsia)",
      "criteria": [
        {
          "factor": "bothersome_at_least_4_days_per_month",
          "met": true
        },
        {
          "factor": "postprandial_fullness",
          "met": true
        },
        {
          "factor": "early_satiation",
          "met": false
        },
        {
          "factor": "epigastric_pain_or_burning_not_associated_with_defecation",
          "met": false
        },
        {
          "factor": "not_explained_by_another_condition",
          "met": true
        },
        {
          "factor": "fulfilled_at_least_2_months",
          "met": true
        },
        {
          "value": 1,
          "factor": "symptoms_met_ge_1",
          "met": true
        }
      ],
      "rome_iv_child_dyspepsia": true,
      "symptoms_met": 1
    },
    {
      "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": "Hyams JS, Di Lorenzo C, Saps M, Shulman RJ, Staiano A, van Tilburg M",
        "doi": "10.1053/j.gastro.2016.02.015",
        "id": "hyams-2016",
        "pmid": "27144632",
        "source": "Gastroenterology. 2016;150(6):1456-1468",
        "title": "Childhood Functional Gastrointestinal Disorders: Child/Adolescent"
      },
      "formula": "rome_iv_child_dyspepsia",
      "formula_expression": "rome_iv_child_dyspepsia iff bothersome_at_least_4_days_per_month and symptoms_met >= 1 and not_explained_by_another_condition and fulfilled_at_least_2_months; symptoms_met counts postprandial_fullness, early_satiation, and epigastric_pain_or_burning_not_associated_with_defecation; H2a item 4 is the exclusion not_explained_by_another_condition, not a fourth symptom; PDS and EPS subtype supportive features are copy-only and are not parsed (Hyams 2016 Rome IV H2a Functional Dyspepsia)",
      "criteria": [
        {
          "factor": "bothersome_at_least_4_days_per_month",
          "met": true
        },
        {
          "factor": "postprandial_fullness",
          "met": true
        },
        {
          "factor": "early_satiation",
          "met": false
        },
        {
          "factor": "epigastric_pain_or_burning_not_associated_with_defecation",
          "met": false
        },
        {
          "factor": "not_explained_by_another_condition",
          "met": true
        },
        {
          "factor": "fulfilled_at_least_2_months",
          "met": true
        },
        {
          "value": 1,
          "factor": "symptoms_met_ge_1",
          "met": true
        }
      ],
      "rome_iv_child_dyspepsia": true,
      "symptoms_met": 1
    }
  ]
}
```

## Response fields

- `formula` (string): rome_iv_child_dyspepsia
- `formula_expression` (string): Hyams 2016 Rome IV H2a: bothersome at least 4 days per month, at least 1 of 3 symptoms, exclusion (item 4, not a fourth symptom), and 2-month duration; PDS and EPS subtype supportive features are copy-only
- `symptoms_met` (integer): Count of true H2a symptoms among postprandial fullness, early satiation, and epigastric pain or burning not associated with defecation (0-3)
- `rome_iv_child_dyspepsia` (boolean): true only when bothersome at least 4 days per month, at least one H2a symptom, the exclusion, and 2-month duration all hold. Not a diagnosis.
- `criteria` (array): Per-factor rows with factor and met; symptoms_met_ge_1 includes value 0-3
- `citation` (object): Hyams 2016 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": "Hyams JS, Di Lorenzo C, Saps M, Shulman RJ, Staiano A, van Tilburg M",
    "doi": "10.1053/j.gastro.2016.02.015",
    "id": "hyams-2016",
    "pmid": "27144632",
    "source": "Gastroenterology. 2016;150(6):1456-1468",
    "title": "Childhood Functional Gastrointestinal Disorders: Child/Adolescent"
  },
  "formula": "rome_iv_child_dyspepsia",
  "formula_expression": "rome_iv_child_dyspepsia iff bothersome_at_least_4_days_per_month and symptoms_met >= 1 and not_explained_by_another_condition and fulfilled_at_least_2_months; symptoms_met counts postprandial_fullness, early_satiation, and epigastric_pain_or_burning_not_associated_with_defecation; H2a item 4 is the exclusion not_explained_by_another_condition, not a fourth symptom; PDS and EPS subtype supportive features are copy-only and are not parsed (Hyams 2016 Rome IV H2a Functional Dyspepsia)",
  "criteria": [
    {
      "factor": "bothersome_at_least_4_days_per_month",
      "met": true
    },
    {
      "factor": "postprandial_fullness",
      "met": true
    },
    {
      "factor": "early_satiation",
      "met": false
    },
    {
      "factor": "epigastric_pain_or_burning_not_associated_with_defecation",
      "met": false
    },
    {
      "factor": "not_explained_by_another_condition",
      "met": true
    },
    {
      "factor": "fulfilled_at_least_2_months",
      "met": true
    },
    {
      "value": 1,
      "factor": "symptoms_met_ge_1",
      "met": true
    }
  ],
  "rome_iv_child_dyspepsia": true,
  "symptoms_met": 1
}
```

## Errors

- HTTP 400 `invalid_rome_iv_child_dyspepsia`: Rome IV child functional dyspepsia needs the Hyams 2016 child/adolescent H2a flags. Returned before settlement; you are not charged.
- 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

- [Rome IV FD](https://magentlab.com/docs/rome-iv-fd) — Apply the Stanghellini 2016 Rome IV B1 functional dyspepsia criteria and return whether PDS (B1a), EPS (B1b), and the published FD box hold (rome_iv_fd).
- [Rome IV child IBS](https://magentlab.com/docs/rome-iv-child-ibs) — Apply the Hyams 2016 Rome IV H2b child/adolescent IBS diagnostic criteria and return stool_features_met (0-3) and whether the published H2b box holds (rome_iv_child_ibs).

## 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.