# Rome IV H1a Child/Adolescent Cyclic Vomiting Syndrome Checker (Hyams 2016)

> Rome IV H1a Child/Adolescent Cyclic Vomiting Syndrome Checker (Hyams 2016) is a paid API for AI agents from api.magentlab.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-14).

Applies the Rome IV H1a criteria (Hyams 2016) to determine whether a child or adolescent meets the diagnostic criteria for cyclic vomiting syndrome (CVS).

## Facts

- Endpoint: GET https://api.magentlab.com/api/calc/rome_iv_child_cvs
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/rome-iv-h1a-child-adolescent-cyclic-vomiting-syndrome-checker-hyams-0f856a64
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_U-Q_rmSG7nUainuh5t564

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability rome-iv-h1a-child-adolescent-cyclic-vomiting-syndrome-checker-hyams-0f856a64
```

Example prompt: Check if this child meets Rome IV H1a cyclic vomiting syndrome criteria: they've had two or more episodes of intense nausea and paroxysmal vomiting lasting hours to days within 6 months (true), the episodes are stereotypical (true), they return to baseline health between episodes separated by weeks to months (true), and the symptoms have not been attributed to another condition (true).

## When to prefer this

Use this endpoint when you need to programmatically apply the Hyams 2016 Rome IV H1a criteria specifically for cyclic vomiting syndrome in children and adolescents, and the caller has already assessed the four clinical flags from clinical evaluation. Do not use for adult CVS (different Rome IV criteria), neonates/toddlers (Rome IV G3), or cannabinoid hyperemesis syndrome.

## Known failure modes

- Missing required query parameter returns an error — all four boolean flags must be supplied
- Misassignment of flags by the caller leads to incorrect logical output (endpoint trusts caller's clinical assessment)
- Not applicable to neonates/toddlers (Rome IV G3 criteria differ), adults (adult Rome IV CVS criteria differ), or cannabinoid hyperemesis syndrome

## How this service works

Hyams 2016 Rome IV H1a child/adolescent cyclic vomiting. rome_iv_child_cvs is true iff two_or_more_periods_intense_nausea_paroxysmal_vomiting_hours_to_days_within_6_months, episodes_stereotypical, episodes_separated_weeks_to_months_with_return_to_baseline, and not_attributed_to_another_condition. Caller assigns four flags. magent does not examine the child. Not a diagnosis, not neonate/toddler G3, not adult Rome IV CVS, not cannabinoid hyperemesis.

## Output

Returns a boolean field rome_iv_child_cvs indicating whether all four Rome IV H1a criteria for child/adolescent cyclic vomiting syndrome are simultaneously satisfied. True only if all four caller-assigned flags are true; false otherwise. Does not provide a clinical diagnosis.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "headers": {
     "type": "object",
     "additionalProperties": {
      "type": "string"
     }
    },
    "queryParams": {
     "type": "object",
     "required": [
      "two_or_more_periods_intense_nausea_paroxysmal_vomiting_hours_to_days_within_6_months",
      "episodes_stereotypical",
      "episodes_separated_weeks_to_months_with_return_to_baseline",
      "not_attributed_to_another_condition"
     ],
     "properties": {
      "episodes_stereotypical": {
       "type": "boolean",
       "description": "Episodes are stereotypical in each patient, as assigned (Hyams 2016 Rome IV H1a). true or false as assigned by the caller. magent does not examine the child."
      },
      "not_attributed_to_another_condition": {
       "type": "boolean",
       "description": "After appropriate medical evaluation, the symptoms cannot be attributed to another condition, as assigned (Hyams 2016 Rome IV H1a). true or false as assigned by the caller. magent does not examine the child."
      },
      "episodes_separated_weeks_to_months_with_return_to_baseline": {
       "type": "boolean",
       "description": "Episodes are separated by weeks to months with return to baseline health between episodes, as assigned (Hyams 2016 Rome IV H1a). true or false as assigned by the caller. magent does not examine the child."
      },
      "two_or_more_periods_intense_nausea_paroxysmal_vomiting_hours_to_days_within_6_months": {
       "type": "boolean",
       "description": "Two or more periods of intense, unremitting nausea and paroxysmal vomiting lasting hours to days within a 6-month period, as assigned (Hyams 2016 Rome IV H1a). true or false as assigned by the caller. magent does not examine the child."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/rome-iv-h1a-child-adolescent-cyclic-vomiting-syndrome-checker-hyams-0f856a64/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.magentlab.com](https://www.zero.xyz/host/api.magentlab.com/llms.txt)