# Rome II IBS Calculator (Thompson 1999)

> Rome II IBS Calculator (Thompson 1999) 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).

Computes the Rome II criteria for irritable bowel syndrome given four caller-assigned boolean flags about abdominal symptoms over the past 12 months.

## Facts

- Endpoint: GET https://api.magentlab.com/api/calc/rome_ii_ibs
- 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-ii-ibs-calculator-thompson-1999-ec84c1ce
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_HGlZqiIgh29OSp5lHEn6b

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-ii-ibs-calculator-thompson-1999-ec84c1ce
```

Example prompt: Check if this patient meets Rome II IBS criteria: they've had abdominal pain for at least 12 weeks in the past 12 months (true), relief with defecation (true), onset associated with change in stool frequency (false), and onset associated with change in stool form (true).

## When to prefer this

Use this endpoint when you need a fast, programmatic Rome II (Thompson 1999) IBS criterion check and already have the four boolean symptom flags from clinical observation or chart review. Prefer this over manual scoring when building clinical decision support tools, EHR integrations, or medical education apps. Do not use this for Rome III, Rome IV, Manning criteria, or IBS subtype classification — those require different endpoints or logic.

## Known failure modes

- Missing required boolean parameters returns a validation error
- Non-boolean values for flags may cause a 400 bad request
- If fewer than two supporting features are true, rome_ii_ibs is false even if the 12-week criterion is met
- No patient examination is performed — accuracy depends entirely on caller-assigned flags

## How this service works

Thompson 1999 Rome II IBS. rome_ii_ibs is true iff at least 12 weeks (need not be consecutive) in the preceding 12 months of abdominal discomfort or pain and at least two of: relieved with defecation, onset associated with a change in stool frequency, and onset associated with a change in stool form. supporting_features_met is 0-3. Caller assigns four flags. magent does not examine the patient. Not a diagnosis, not Rome III, not Rome IV, not Manning, not IBS subtype.

## Output

Returns a rome_ii_ibs boolean (true if criteria met) and a supporting_features_met count (0–3) reflecting how many of the three IBS supporting features were flagged true by the caller.

## 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": [
      "pain_or_discomfort_12_weeks_of_12_months",
      "relieved_with_defecation",
      "onset_change_stool_frequency",
      "onset_change_stool_form"
     ],
     "properties": {
      "onset_change_stool_form": {
       "type": "boolean",
       "description": "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."
      },
      "relieved_with_defecation": {
       "type": "boolean",
       "description": "Abdominal discomfort or pain relieved with defecation (one of three supporting features; at least two required). true or false as assigned by the caller."
      },
      "onset_change_stool_frequency": {
       "type": "boolean",
       "description": "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."
      },
      "pain_or_discomfort_12_weeks_of_12_months": {
       "type": "boolean",
       "description": "At least 12 weeks (need not be consecutive) in the preceding 12 months of abdominal discomfort or pain (Thompson 1999). true or false as assigned by the caller. magent does not examine the patient."
      }
     }
    }
   },
   "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-ii-ibs-calculator-thompson-1999-ec84c1ce/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)