large intestine
Enable an AI agent to recognise a large intestine, record its segment-specific condition and function, and assess which observations or interventions require further evidence or authorization.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
Researched by: Codex
Purpose and description
Enable an AI agent to recognise a large intestine, record its segment-specific condition and function, and assess which observations or interventions require further evidence or authorization.
It can be Map observations and samples to the correct large-intestinal segment and anatomical configuration.; Compare serial measurements while accounting for preparation, distension and measurement method.; Identify missing evidence needed to distinguish structural narrowing, altered motility and evacuation difficulty.; Assess anatomical reach and evidence limitations for proposed imaging, endoscopy or sampling.; Flag documented tissue or passage abnormalities that require qualified review before intervention.; Track how resection, diversion or reconstruction changes continuity, retained regions and expected functional assessment..
Distinguishing features
Confirm identity through species-appropriate position and continuity within the distal intestinal tract; diameter alone is insufficient.
Distinguish the whole large intestine from the colon: document which additional regions the adopted anatomical convention includes.
For human anatomy, use caecal, colonic and rectal landmarks to distinguish regions; do not require every segment to exhibit the same external features.
When histology is available, assess whether the regional mucosal pattern supports large-intestinal rather than small-intestinal identity, allowing for disease and altered anatomy.
Distinguish retained native large intestine from an ileal pouch or other surgically substituted conduit using operative history and tissue origin.
Scope
+ Species-specific anatomical boundaries, constituent segments and continuity with neighbouring bowel
+ Native, variant, resected, reconstructed and diverted large-intestinal anatomy
+ Segment-specific wall integrity, perfusion, inflammation and structural abnormalities
+ Luminal contents, passage, storage and evacuation contribution
+ Water and electrolyte handling and local microbial activity
+ Evidence and anatomical constraints relevant to examination, sampling and intervention
- Small-intestinal anatomy and digestion except at the junction with the large intestine
- Whole-organism nutrition, hydration and systemic disease management
- Microbial taxa and communities as independently modelled biological entities
- Pelvic floor and anal sphincter apparatus beyond their functional interfaces
- Disease classification, cancer staging and treatment protocols as independent models
- Endoscopes, surgical instruments, medications and ostomy appliances as products
Characteristics
- Host species and life stage
- Species identifier; developmental or life-stage category Determines which anatomy and functional reference evidence apply.
- Included anatomical regions
- Named segments linked to a declared anatomical terminology Prevents colon-only observations from being attributed to the entire large intestine.
- Continuity and outlet configuration
- Native continuity; anastomosed; diverted; discontinuous; partially resected; unknown Determines the path of contents and which regions an examination can reach.
- Segment dimensions
- Length in cm; luminal diameter and wall thickness in mm, with segment, method and distension context Supports comparison of narrowing, dilation and wall change without treating unlike measurements as equivalent.
- Wall condition
- Observed mucosal and deeper-wall abnormalities, extent, severity and uncertainty Separates superficial findings from damage that may affect containment or intervention feasibility.
- Perfusion evidence
- Adequate; impaired; indeterminate; unassessed, with supporting method and location Relates tissue condition to blood supply without inferring perfusion from appearance alone.
- Luminal contents
- Recorded stool consistency, gas, fluid, retained material and distribution Provides context for distension, passage and examination visibility.
- Regional transit
- Hours, with protocol, segment coverage and observation interval Distinguishes measured movement through the large intestine from stool frequency alone.
- Water and electrolyte handling
- Water balance in mL/day and electrolyte quantities in mmol/day when attributable; otherwise explicitly indirect evidence Prevents whole-body or stool measurements from being mistaken for direct organ-level transport measurements.
- Local microbial evidence
- Links to samples, collection sites, assays and microbial or metabolite observations Keeps stool-derived evidence distinct from evidence about a particular intestinal region.
Also called
Where this came from
wikidata · CC0 1.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 5 bundles · 10 layers · 10 findings · 20 questions.
Anatomical identity and continuity Establish which large intestine is represented and how its regions connect.
Species differences, terminology and surgery can otherwise cause an agent to identify the wrong tissue or assume a nonexistent route.
Regional boundaries
Declare the anatomical convention and locate the organ's constituent regions.
Large-intestine extent
Record the included regions and observed proximal and distal boundaries.
- For this species and terminology, which regions belong to the large intestine, including the status of the appendix and anal canal where applicable? boundary
- Which observed landmarks distinguish this structure from small intestine and distinguish the whole organ from its colon component? definition
Altered bowel topology
Represent native connections and changes caused by development or procedures.
Retained segments and routes
Record retained, absent, bypassed and substituted regions together with their connections.
- Which segments remain connected to the incoming bowel and to a natural or surgically created outlet? boundary
- Which operative records, imaging or direct observations establish each resection, anastomosis, diversion or tissue substitution? provenance
Wall condition and perfusion Describe the intestinal wall as a barrier, structural tube and living tissue.
A patent lumen does not establish intact mucosa, viable tissue or containment.
Mucosal and deeper-wall state
Localise tissue changes by segment and depth.
Wall abnormality extent
Record observed lesions, inflammation and wall changes without converting appearance into an unsupported diagnosis.
- Which segment and wall layers show abnormalities, and what are their measured extent and appearance? measurement
- Was the finding established by endoscopy, imaging, histology or another method, and which tissue depths could that method assess? provenance
Viability and containment
Track evidence about blood supply and separation of the lumen from surrounding spaces.
Perfusion and wall-breach evidence
Distinguish demonstrated impairment or leakage from suspicion and unassessed status.
- What location-specific evidence supports adequate or impaired perfusion, and when was it obtained? provenance
- Is there evidence of a wall breach, leak or abnormal connection, and which compartments or structures are involved? boundary
Luminal passage and evacuation Represent contents, available passage and movement through the large intestine.
Retention can reflect structural, motor or outlet-related problems that require different evidence.
Lumen and contents
Describe regional calibre and the distribution of material within the bowel.
Passage geometry
Record narrowing, dilation and retained contents with measurement context.
- Where are narrowing, dilation or retained contents observed, and what dimensions or extent were measured? measurement
- How did bowel preparation, insufflation, filling or decompression affect the observed lumen? provenance
Transit and outlet interface
Separate movement through the organ from passage through its outlet.
Regional movement and emptying
Record transit and emptying evidence without using stool frequency as a complete functional assessment.
- What regional or whole-large-intestine transit was measured, using which protocol and observation period? measurement
- Which findings localise impaired passage within the large intestine, and which instead concern the pelvic floor or outlet apparatus? boundary
Fluid handling and luminal ecology Capture evidence about fluid exchange and microbial processes within the large-intestinal lumen.
Luminal state depends on exchange and biological activity as well as transit, but common samples provide only partial evidence.
Water and electrolyte exchange
Represent measured or inferred contributions to fluid and electrolyte handling.
Exchange evidence and attribution
Record what can be attributed to the large intestine and what remains a whole-organism observation.
- Which measurements support an estimate of large-intestinal water or electrolyte exchange, and in what units? measurement
- How are incoming small-intestinal contents, transit, resection and diversion accounted for when attributing the observation to this organ? boundary
Microbial activity and sampling
Connect local microbial observations to their sampling and analytical limitations.
Luminal ecology evidence
Record microbial and metabolite evidence without assuming that a stool sample describes every region.
- Was the sample collected from stool, luminal contents or mucosa, and which large-intestinal region can it represent? provenance
- Which microbial activities or metabolites were measured, and which functional interpretations remain unverified? measurement
Examination and intervention constraints Connect the organ's current anatomy and condition to proposed examinations and interventions.
An agent needs to distinguish an accessible segment from an adequately assessed segment and a proposed action from an authorized one.
Examination coverage
Record which regions and tissue aspects an examination actually evaluated.
Reach, visibility and sample location
Preserve coverage gaps that could otherwise be mistaken for normal findings.
- Which segments were reached or visualised, and where did preparation, narrowing, altered anatomy or technical limits reduce coverage? boundary
- How is each biopsy or other sample linked to its collection site and examination record? provenance
Action eligibility and follow-up
Record the evidence, authority and expected anatomical consequences of a proposed action.
Large-intestinal action constraints
Make procedure-specific constraints and reassessment requirements explicit without supplying a treatment protocol.
- For the proposed preparation, instrumentation, sampling or surgery, what documented anatomy and tissue findings require qualified assessment before proceeding? action
- Who authorized the action, and which changes to continuity, wall integrity, passage or fluid handling must be recorded afterward? action
What the second pass must settle
- Does this registry entry intend human anatomy only or a cross-species concept, and which anatomical terminology should govern its boundaries?
- Should the appendix and anal canal be constituent regions or linked neighbouring models under the registry's chosen convention?
- Which species-, age-, segment- and method-specific reference evidence can support interpretation of calibre, wall thickness and transit?
- Which measurements can reliably attribute fluid exchange or microbial function to a particular large-intestinal region rather than infer it from stool or systemic observations?
- Does an existing Vercy world model already own this concept, and which reviewed sources and clinical governance rules should support any eventual action constraints?