GI · LIVE

Bristol stool form scale (Lewis 1997)

Bristol stool

Return the Lewis 1997 Bristol stool form scale type 1-7 from a caller-assigned integer, with the published form wording.

LIVE $0.005 USDC GET /api/calc/bristol_stool

Markdown: /docs/bristol-stool.md · Canonical: https://magentlab.com/docs/bristol-stool

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

What it computes

Return the Lewis 1997 Bristol stool form scale type 1-7 from a caller-assigned integer, with the published form wording.

When to use

When an agent already has a Bristol stool form type 1-7 as in Lewis 1997 and needs that type echoed. magent does not inspect stool. Not a diagnosis and not a Rome IBS subtype.

When not to use

Not a medical device.
Not a diagnosis. magent does not inspect stool.
The caller assigns stool_type 1-7. magent does not examine the patient.
Lewis 1997 showed stool form correlates with whole-gut transit time. This tool echoes the assigned type only. It does not assign constipation, diarrhea, or Rome IBS subtype.

Formula

stool_type = caller-assigned integer 1-7 (Lewis 1997 Bristol stool form scale); the tool echoes stool_type; stool form correlates with whole-gut transit time; no constipation or diarrhea bands

Citation

Title: Stool form scale as a useful guide to intestinal transit time
Authors: Lewis SJ, Heaton KW
Source: Scand J Gastroenterol. 1997;32(9):920-924
DOI: 10.3109/00365529709011203

Worked example

Type 4 sausage or snake, smooth and soft

Given: stool_type=4

stool_type 4 → like a sausage or snake, smooth and soft
score 4; max 7

Also searched as

Bristol stool scale
Bristol stool form scale
Bristol stool type
stool form scale
Lewis Heaton stool form
Lewis 1997 stool form
BSFS
stool type 1-7

Try

Opens the live endpoint. Unpaid browser requests show the paywall; agents should send Accept: application/json.

/api/calc/bristol_stool?stool_type=4

Full URL: https://api.magentlab.com/api/calc/bristol_stool?stool_type=4

Call

Expect HTTP 402 until you retry with PAYMENT-SIGNATURE. Incomplete query params return HTTP 400 before any quote or charge.

curl -i -H "Accept: application/json" "https://api.magentlab.com/api/calc/bristol_stool?stool_type=4"

Parameters

Name	Type	Required	Description
`stool_type`	integer	required	Lewis 1997 Bristol stool form scale type 1-7 as assigned by the caller (1 separate hard lumps, like nuts; 2 sausage-shaped but lumpy; 3 like a sausage but with cracks on its surface; 4 like a sausage or snake, smooth and soft; 5 soft blobs with clear-cut edges; 6 fluffy pieces with ragged edges, a mushy stool; 7 watery, no solid pieces, entirely liquid). magent does not inspect stool.

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.

POST /api/calc/bristol_stool Max 25 unit_amount + extra_item_amount * (n - 1) extra $0.002 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 (fixture)

{
  "items": [
    {
      "stool_type": "4"
    },
    {
      "stool_type": "4"
    }
  ]
}

Open bulk paywall →

Opens a two-item fixture on the API host. Unpaid browsers get the same MetaMask paywall as GET; Pay retries POST with those items.

Example 200 (fixture)

{
  "count": 2,
  "path": "/api/calc/bristol_stool",
  "items": [
    {
      "description": "Like a sausage or snake, smooth and soft",
      "components": [
        {
          "factor": "stool_type",
          "points": 4,
          "present": true
        }
      ],
      "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": "Lewis SJ, Heaton KW",
        "doi": "10.3109/00365529709011203",
        "id": "lewis-heaton-1997",
        "pmid": "9299672",
        "source": "Scand J Gastroenterol. 1997;32(9):920-924",
        "title": "Stool form scale as a useful guide to intestinal transit time"
      },
      "formula": "bristol_stool",
      "formula_expression": "stool_type = caller-assigned integer 1-7 (Lewis 1997 Bristol stool form scale); the tool echoes stool_type; stool form correlates with whole-gut transit time; no constipation or diarrhea bands",
      "max_score": 7,
      "score": 4,
      "stool_type": 4
    },
    {
      "description": "Like a sausage or snake, smooth and soft",
      "components": [
        {
          "factor": "stool_type",
          "points": 4,
          "present": true
        }
      ],
      "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": "Lewis SJ, Heaton KW",
        "doi": "10.3109/00365529709011203",
        "id": "lewis-heaton-1997",
        "pmid": "9299672",
        "source": "Scand J Gastroenterol. 1997;32(9):920-924",
        "title": "Stool form scale as a useful guide to intestinal transit time"
      },
      "formula": "bristol_stool",
      "formula_expression": "stool_type = caller-assigned integer 1-7 (Lewis 1997 Bristol stool form scale); the tool echoes stool_type; stool form correlates with whole-gut transit time; no constipation or diarrhea bands",
      "max_score": 7,
      "score": 4,
      "stool_type": 4
    }
  ]
}

Response

Field	Type	Description
`formula`	string	bristol_stool
`formula_expression`	string	Published type-echo rule
`stool_type`	integer	Caller-assigned Bristol stool form scale type 1-7
`score`	integer	Same as stool_type
`max_score`	integer	7
`description`	string	Lewis 1997 form wording for that type
`components`	array	stool_type component
`citation`	object	Lewis and Heaton 1997
`disclaimer`	string	Not a medical device

Example JSON

Machine form of the same example. Frozen fixture. Not a live lookup.

{
  "description": "Like a sausage or snake, smooth and soft",
  "components": [
    {
      "factor": "stool_type",
      "points": 4,
      "present": true
    }
  ],
  "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": "Lewis SJ, Heaton KW",
    "doi": "10.3109/00365529709011203",
    "id": "lewis-heaton-1997",
    "pmid": "9299672",
    "source": "Scand J Gastroenterol. 1997;32(9):920-924",
    "title": "Stool form scale as a useful guide to intestinal transit time"
  },
  "formula": "bristol_stool",
  "formula_expression": "stool_type = caller-assigned integer 1-7 (Lewis 1997 Bristol stool form scale); the tool echoes stool_type; stool form correlates with whole-gut transit time; no constipation or diarrhea bands",
  "max_score": 7,
  "score": 4,
  "stool_type": 4
}

Client errors (HTTP 400)

Invalid params return 400 without charge. Shared HTTP 402 and 503 meanings: Payments.

HTTP	Code	When
400	`invalid_bristol_type`	stool_type must be an integer from 1 to 7 (Lewis 1997). Returned before settlement; you are not charged.
400	`invalid_items`	POST body must be a JSON object with only an items array Returned before settlement; you are not charged.
400	`invalid_item_count`	items must be an array of 1 to 25 objects Returned before settlement; you are not charged.
400	`invalid_item`	each items entry must be a JSON object Returned before settlement; you are not charged.

Related tools

Rome III IBS — Apply the Longstreth 2006 Rome III IBS diagnostic criteria and return supporting_features_met (0-3) and whether the published IBS box holds (rome_iii_ibs).
Rome IV IBS — Apply the Mearin 2016 Rome IV IBS diagnostic criteria and return supporting_features_met (0-3) and whether the published IBS box holds (rome_iv_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. Unpaid valid requests return HTTP 402 with a base64 PAYMENT-REQUIRED header. HTTP 503 is not a new quote: retry the same PAYMENT-SIGNATURE. Full handshake and shared payment errors: Payments. Stdio MCP: /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.