# Rome IV Functional Defecation Disorder Calculator (Rao 2016)

> Rome IV Functional Defecation Disorder Calculator (Rao 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).

Evaluates Rome IV criteria for Functional Defecation Disorder (F3) based on caller-supplied test results and history flags, returning a boolean diagnosis indicator and count of met evacuation tests.

## Facts

- Endpoint: GET https://api.magentlab.com/api/calc/rome_iv_functional_defecation
- 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-functional-defecation-disorder-calculator-rao-2016-97ded389
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_lQGvbZP1c3pc9B4NtWaPd

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-functional-defecation-disorder-calculator-rao-2016-97ded389
```

Example prompt: Does this patient meet Rome IV criteria for functional defecation disorder? They already satisfy functional constipation criteria, have an abnormal balloon expulsion test and abnormal manometry, normal imaging, symptoms have been present for the last 3 months, and onset was over 6 months ago.

## When to prefer this

Use this endpoint when you have already assembled caller-coded results from balloon expulsion, manometry/EMG, and imaging tests, along with a prior determination of functional constipation or IBS-C, and need a deterministic Rome IV F3 criterion check. Prefer this over manual Rome IV lookup when integrating into a clinical documentation or decision-support pipeline that already encodes anorectal test results as booleans.

## Known failure modes

- Missing any of the six required boolean query parameters returns a validation error
- Non-boolean values for flag parameters cause a schema rejection
- Network or payment errors (402 if payment not provided) prevent the call from completing
- Caller miscoding test results (e.g. inverting a result) will yield a logically valid but clinically incorrect output

## How this service works

Rao 2016 Rome IV F3. rome_iv_functional_defecation is true iff FC and/or IBS-C, at least two of three evacuation tests (balloon expulsion, manometry or anal surface EMG, imaging), last-3-months criteria, and 6-month onset. evacuation_tests_met is 0-3. magent does not perform those tests. Not a diagnosis. Not F3a or F3b as separate diagnoses.

## Output

Returns rome_iv_functional_defecation (true/false) indicating whether the patient meets Rome IV Functional Defecation Disorder criteria, and evacuation_tests_met (integer 0-3) counting how many of the three evacuation tests were flagged as abnormal. Does not perform tests or take history — all inputs are caller-assigned.

## 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": [
      "satisfies_fc_and_or_ibs_with_constipation",
      "abnormal_balloon_expulsion",
      "abnormal_anorectal_evacuation_pattern_manometry_or_emg",
      "impaired_rectal_evacuation_by_imaging",
      "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 (Rao 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 (Rao 2016). true or false as assigned by the caller. magent does not take a history."
      },
      "abnormal_balloon_expulsion": {
       "type": "boolean",
       "description": "Abnormal balloon expulsion test (one of three evacuation tests; at least two required). true or false as assigned by the caller. magent does not perform balloon expulsion."
      },
      "impaired_rectal_evacuation_by_imaging": {
       "type": "boolean",
       "description": "Impaired rectal evacuation by imaging (one of three evacuation tests; at least two required). true or false as assigned by the caller. magent does not perform imaging."
      },
      "satisfies_fc_and_or_ibs_with_constipation": {
       "type": "boolean",
       "description": "The patient already satisfies diagnostic criteria for functional constipation and/or IBS with constipation, as assigned (Rao 2016 F3). true or false as assigned by the caller. magent does not re-run those tools."
      },
      "abnormal_anorectal_evacuation_pattern_manometry_or_emg": {
       "type": "boolean",
       "description": "Abnormal anorectal evacuation pattern with manometry or anal surface EMG (one of three evacuation tests; at least two required). true or false as assigned by the caller. mage
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/rome-iv-functional-defecation-disorder-calculator-rao-2016-97ded389/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)