# Truelove & Witts 1955 Ulcerative Colitis Severity Calculator

> Truelove & Witts 1955 Ulcerative Colitis Severity 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).

Classifies ulcerative colitis severity as mild, moderately severe, or severe using the original Truelove & Witts 1955 criteria based on stool frequency, macroscopic blood, and systemic flags.

## Facts

- Endpoint: GET https://api.magentlab.com/api/calc/truelove_witts
- 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/truelove-witts-1955-ulcerative-colitis-severity-calculator-2cc41d6e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_FKROIWwLrue9k2ABLhOfU

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 truelove-witts-1955-ulcerative-colitis-severity-calculator-2cc41d6e
```

Example prompt: Apply the Truelove and Witts 1955 criteria to classify this UC flare: the patient has 7 stools per day with macroscopic blood, fever present, tachycardia present, no anemia, and ESR not raised.

## When to prefer this

Use this endpoint when you specifically need the original Truelove & Witts 1955 three-tier severity classification (mild / moderately severe / severe) for ulcerative colitis, as opposed to the Mayo UC score, PUCAI (pediatric), or other IBD indices. Ideal for clinical documentation, triage decision support, or referral letters where the 1955 criteria are required by protocol.

## Known failure modes

- Missing required query parameters (stools_per_day, macroscopic_blood, fever, tachycardia, anemia, esr_raised) returns a 400-level error
- stools_per_day outside the expected integer range (0–40) may produce unexpected results
- Payment not provided or insufficient USDC via x402 protocol returns a 402 Payment Required error
- Boolean flags incorrectly assigned by caller (e.g. using a non-1955 definition of anemia) will yield a classification that does not reflect the original criteria

## How this service works

Truelove and Witts 1955 ulcerative colitis severity. severe iff stools_per_day >= 6 with macroscopic blood and at least one of fever, tachycardia, anemia, and esr_raised; mild iff stools_per_day <= 4, macroscopic_blood false, and no systemic flags; otherwise moderately_severe. Caller assigns flags from the 1955 table (fever mean evening >37.5 C or 37.8 C on 2 of 4 days; pulse >90; Hb 75% or less; ESR >30). magent does not examine the patient. Not a diagnosis, not Mayo UC, not PUCAI.

## Output

Returns a severity classification of mild, moderately severe, or severe according to the original Truelove & Witts 1955 table, derived from stool frequency, macroscopic blood presence, and the four systemic flags (fever, tachycardia, anemia, ESR raised). Does not diagnose; does not apply Mayo UC or PUCAI criteria.

## 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": [
      "stools_per_day",
      "macroscopic_blood",
      "fever",
      "tachycardia",
      "anemia",
      "esr_raised"
     ],
     "properties": {
      "fever": {
       "type": "boolean",
       "description": "Fever as assigned by the caller using the 1955 definition: mean evening temperature more than 99.5 F (37.5 C), or a temperature of 100 F (37.8 C) or more on at least two days out of four. true or false. magent does not measure temperature."
      },
      "anemia": {
       "type": "boolean",
       "description": "Anaemia as assigned by the caller using the 1955 definition: haemoglobin 75% or less, allowance made for recent transfusion. true or false. Not the later 10.5 g/dL restatement. magent does not measure haemoglobin."
      },
      "esr_raised": {
       "type": "boolean",
       "description": "E.S.R. much raised as assigned by the caller using the 1955 definition: more than 30 mm in one hour. true or false. magent does not measure ESR."
      },
      "tachycardia": {
       "type": "boolean",
       "description": "Tachycardia as assigned by the caller using the 1955 definition: mean pulse rate more than 90 per minute. true or false. magent does not measure pulse."
      },
      "stools_per_day": {
       "type": "integer",
       "description": "Number of stools (motions) per day as assigned by the caller (integer 0-40). The 1955 mild column is four or less; the severe column is six or more. magent does not count stools."
      },
      "macroscopic_blood": {
       "type": "boolean",
       "description": "Macroscopic blood in stools as in the 1955 severe column (with macroscopic blood). true or false as assigned by the caller. The 1955 mild column allows no more than small amounts; assign false when blood is absent or no more than small amounts. magent does not examine the stool."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "ty
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/truelove-witts-1955-ulcerative-colitis-severity-calculator-2cc41d6e/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)