# Rome IV CNVS (B3a) Criterion Calculator

> Rome IV CNVS (B3a) Criterion Calculator 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).

Evaluates whether a patient meets the Stanghellini 2016 Rome IV Chronic Nausea Vomiting Syndrome (CNVS, B3a) diagnostic criteria based on five caller-assigned boolean flags

## Facts

- Endpoint: GET https://api.magentlab.com/api/calc/rome_iv_cnvs
- 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-cnvs-b3a-criterion-calculator-f9a58713
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_tptDk_3h47gEiFSMVsntt

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-cnvs-b3a-criterion-calculator-f9a58713
```

Example prompt: Check whether this patient meets Rome IV CNVS (B3a) criteria: they have bothersome nausea at least once a week, self-induced vomiting, eating disorders, regurgitation, and rumination have all been excluded, upper endoscopy found no organic explanation, the pattern has been present for the last 3 months, and symptoms started at least 6 months ago.

## When to prefer this

Use this endpoint when you need to programmatically evaluate whether a patient's documented clinical profile satisfies the Stanghellini 2016 Rome IV CNVS (B3a) criteria and the caller has already gathered and assigned the five required boolean flags from clinical history and upper endoscopy results. Prefer this over manual lookup when building EHR integrations, GI decision-support agents, or automated chart-review pipelines that need a deterministic, auditable Rome IV CNVS flag.

## Known failure modes

- Missing any of the five required boolean query parameters returns a validation error
- Non-boolean values passed for flag parameters cause a schema error
- Endpoint does not validate the clinical appropriateness of caller-assigned flags — garbage in, garbage out
- Network or payment (x402) failures return HTTP 402 or 5xx without a criterion result

## How this service works

Stanghellini 2016 Rome IV chronic nausea vomiting syndrome (CNVS, B3a). rome_iv_cnvs is true iff bothersome nausea at least 1 day per week and/or one or more vomiting episodes per week as one flag, self-induced vomiting eating disorders regurgitation and rumination excluded, no organic systemic or metabolic explanation including at upper endoscopy, last-3-months criteria, and 6-month onset. magent does not take a history or read endoscopy. Not a diagnosis, not CVS, not CHS, not rumination.

## Output

Returns a boolean field rome_iv_cnvs indicating true if all five Rome IV CNVS B3a diagnostic criteria are satisfied simultaneously, and false otherwise. The result is a criterion check only, not a clinical diagnosis, and does not cover CVS, CHS, or rumination syndrome.

## 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": [
      "bothersome_nausea_or_vomiting_weekly",
      "self_induced_vomiting_eating_disorders_regurgitation_rumination_excluded",
      "no_organic_systemic_metabolic_explanation",
      "fulfilled_last_3_months",
      "onset_at_least_6_months"
     ],
     "properties": {
      "fulfilled_last_3_months": {
       "type": "boolean",
       "description": "Criteria fulfilled for the last 3 months, as assigned (Stanghellini 2016). true or false as assigned by the caller. magent does not take a history."
      },
      "onset_at_least_6_months": {
       "type": "boolean",
       "description": "Symptom onset at least 6 months prior to diagnosis, as assigned (Stanghellini 2016). true or false as assigned by the caller. magent does not take a history."
      },
      "bothersome_nausea_or_vomiting_weekly": {
       "type": "boolean",
       "description": "Bothersome (severe enough to impact usual activities) nausea at least 1 day per week and/or one or more vomiting episodes per week (Stanghellini 2016 Rome IV CNVS B3a). One caller flag covering nausea and/or vomiting. true or false as assigned by the caller. magent does not take a history."
      },
      "no_organic_systemic_metabolic_explanation": {
       "type": "boolean",
       "description": "No evidence of organic, systemic, or metabolic disease likely to explain the symptoms on routine investigations including at upper endoscopy, as assigned (Stanghellini 2016). true or false as assigned by the caller. magent does not read endoscopy."
      },
      "self_induced_vomiting_eating_disorders_regurgitation_rumination_excluded": {
       "type": "boolean",
       "description": "Self-induced vomiting, eating disorders, regurgitation, and rumination have been excluded (Stanghellini 2016). true or false as assigned by the caller. magent does not take a history."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/rome-iv-cnvs-b3a-criterion-calculator-f9a58713/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)