Skip to main content

K52.1 ICD-10-CM Code: Toxic gastroenteritis and colitis

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Coding at a Glance

Tabular directives
2 inclusion terms · 2 Excludes1 · 1 use-additional code · 1 code-first instruction

Inpatient Payment Groups (MS-DRG)

Potential MS-DRG participation — not a DRG assignment.

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v44, Appendix B.

  • MS-DRG 393 — OTHER DIGESTIVE SYSTEM DIAGNOSES WITH MCC (MDC 06)
  • MS-DRG 394 — OTHER DIGESTIVE SYSTEM DIAGNOSES WITH CC (MDC 06)
  • MS-DRG 395 — OTHER DIGESTIVE SYSTEM DIAGNOSES WITHOUT CC/MCC (MDC 06)
  • MS-DRG 791 — PREMATURITY WITH MAJOR PROBLEMS (MDC 15)
  • MS-DRG 793 — FULL TERM NEONATE WITH MAJOR PROBLEMS (MDC 15)

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for K52.1 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2027Effective: October 1, 2026

Trace:FY2027 changesChange historyRelease, file and checksum

Notes without a marker are published on K52.1 itself; “inherited from” names the category or block whose note applies here.

Includes

Conditions the official ICD-10-CM tabular list includes under this code.

  • noninfective inflammatory bowel disease

Source: inherited from K50-K52

Inclusion Terms

Alternative terms the tabular list files under this code.

  • Drug-induced gastroenteritis and colitis

Excludes1 — Not Coded Here

Conditions generally not reported together with this code (Excludes1) -- an error unless the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Source: inherited from K50-K52

Code First

Underlying conditions that must be sequenced before this code.

Use Additional Code

Supplementary codes the tabular list directs you to add.

  • Use additional code for adverse effect, if applicable, to identify drug (T36-T50 with fifth or sixth character 5)

Coder workflow for K52.1

MedCoder structured workflow — derived from this code’s own official record

Before you code K52.1

  1. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with K52.1. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).

    See the official tabular notes

Choose the right path

  1. Does the documentation support a condition named in K52.1’s Excludes1 note?
    Yes → Do not simply proceed: review the excluded code. Both are reported only when the record shows the two conditions are unrelated.
    No → Continue.

    ReviewK58, K59.3

  2. Is the underlying (etiologic) condition the Code First note names documented?
    Yes → Sequence the underlying condition first, then K52.1.
    No → Continue; do not add an underlying condition the record does not document.

Consider K52.1. Then work the Use Additional Code note, and confirm the code is valid for the date of service in the Verify section.

Documentation check

The provider’s diagnostic statement
Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).
The underlying (etiologic) condition
Named in the Code First note; sequenced before this code when documented (Guidelines I.A.13).
The conditions the Use Additional Code note names
Reported with this code when documented; a conditional instruction (“if applicable”, “if known”) applies only when the record supports it.

Official instructions as workflow

  • Excludes1 — check before selecting K52.1(2 notes)

    Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with K52.1: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

    CompareK58, K59.3

    See the official tabular notes · Guidelines I.A.12.a

  • Code First — sequencing check(1 note)

    Coding workflow: Check whether the underlying or etiologic condition the note names is documented. When it is, sequence it before K52.1. Do not add an underlying condition the record does not document.

    See the official tabular notes · Guidelines I.A.13

  • Use Additional Code — after identifying K52.1(1 note)

    Coding workflow: Check whether the documentation supports the additional code(s) the note names, and report them with K52.1 when it does. Where the instruction is conditional (“if applicable”, “if known”), it applies only when the record documents the condition.

    See the official tabular notes · Guidelines I.A.13

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

Documentation: Both the condition K52.1 describes and a condition named in its Excludes1 note are documented for the same encounter.

Coding question: Can both codes be reported?

Path: Review the Excludes1 note and the excluded code, and look for a provider statement on whether the two conditions are related.

Reason: Excludes1 means the two are not coded together; the exception is when the record shows the conditions are unrelated to each other (Guidelines I.A.12.a).

ReviewK58, K59.3

Documentation: The underlying condition the Code First note names is documented alongside this condition.

Coding question: How are the two sequenced?

Path: Review the Code First note.

Reason: The underlying condition is sequenced first and the manifestation follows (Guidelines I.A.13).

Documentation: A condition the Use Additional Code note names is documented.

Coding question: Is a second code reported with K52.1?

Path: Review the Use Additional Code note and the code it names.

Reason: The additional code is reported when the record documents the condition; a conditional instruction applies only when its condition is met (Guidelines I.A.13).

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Coding context

The comparisons, hierarchy, index entries, guidelines, relationships, risk-adjustment and coverage context a coder commonly needs. Each section names whether it is official source data, a MedCoder-derived relationship or MedCoder editorial.

Don’t confuse K52.1 with…

MedCoder analysis — pairs from this code’s official notes, distinctions written by MedCoder

The codes most likely to be picked instead of K52.1 — named in its own official notes, or sharing its laterality or encounter family — with what separates them and which documentation moves the case. Each links to the full comparison.

  • K58— Excludes1 conflict (Excludes1 — generally not reported together)

    Not coded here — the tabular list excludes this pair for the same encounter.

    Not reported together with this code, except where the two conditions are documented as unrelated.

    What moves you there: Documentation of irritable bowel syndrome moves the case to K58; the two are not reported together unless documented as unrelated.

    Full comparison: K52.1 vs K58 →

  • K59.3— Excludes1 conflict (Excludes1 — generally not reported together)

    Not coded here — the tabular list excludes this pair for the same encounter.

    Not reported together with this code, except where the two conditions are documented as unrelated.

    What moves you there: Documentation of megacolon moves the case to K59.3; the two are not reported together unless documented as unrelated.

    Full comparison: K52.1 vs K59.3 →

  • K52.9— Specificity relationship (Review)

    Overlapping diagnoses in the same category.

    Overlapping codes in the same category — the documentation decides which is the more specific fit.

    What moves you there: A record that documents no more than “Noninfective gastroenteritis and colitis, unspecified” takes K52.9; specificity in the record moves it back here.

    Full comparison: K52.1 vs K52.9 →

Relationships are read from this code's own official notes, its laterality siblings and its encounter family; the wording of each distinction is MedCoder editorial, and the documentation named in each “what moves you there” line is the official note phrase or sibling title itself. Source: CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a.

Code Overview

Toxic gastroenteritis and colitis is a billable ICD-10-CM diagnosis code (K52.1).

MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.

Indexed Clinical Terms (18)

Official source data — entries quoted as published, in the Index’s own lookup phrasing

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code. These are alphabetic-index entries shown as the Index writes them — lookup phrasing, not necessarily the wording of a final diagnosis.

Official Coding Guidelines

No excerpt in the ICD-10-CM Official Guidelines names this code specifically. Its chapter carries only this chapter-wide note:

Chapter 11: Diseases of the Digestive System (K00-K95)

Reserved for future guideline expansion

Decision Points

The directives on this code's own record, as a pre-claim checklist.

  1. Sequencing: 1 Code First instruction — the underlying condition is sequenced before this code when present. See the Code First notes
  2. 1 Use Additional Code instruction — report the named additional code(s) when the documentation supports them. See the Use Additional Code notes
  3. 2 Excludes1 entries — codes named there are generally not reported together with this code (Guidelines I.A.12.a). See the Excludes1 notes

Checklist rows are derived from this code's own official directives; the wording of each check is MedCoder editorial. The official notes themselves are in the sections each row links to.

Verify Before Coding

  • CC as a secondary diagnosis (FY2027). Can raise the stay's MS-DRG severity tier.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder structured relationships — computed from published CMS and AHRQ datasets

MS-DRG Grouper Relationships (FY2027)

Potential MS-DRG participation — not a DRG assignment.

FY2027 MS-DRG: CC — Complication or Comorbidity. Reported as a secondary diagnosis, this code raises the stay's MS-DRG severity tier — except when the principal diagnosis is one of 1 clinically related codes on its CMS exclusion list.

Named in the grouper logic of 5 MS-DRGs: DRG 393 (MDC 06), DRG 394 (MDC 06), DRG 395 (MDC 06), DRG 791 (MDC 15), DRG 793 (MDC 15).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):DIG022 — Noninfectious gastroenteritis (default); INJ030 — Drug induced or toxic related condition.

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical categories (Noninfectious gastroenteritis, Drug induced or toxic related condition).

H91.02 — Ototoxic hearing loss, left ear, H91.03 — Ototoxic hearing loss, bilateral, H91.09 — Ototoxic hearing loss, unspecified ear, I42.7 — Cardiomyopathy due to drug and external agent, I95.2 — Hypotension due to drugs, J70.2 — Acute drug-induced interstitial lung disorders, J70.3 — Chronic drug-induced interstitial lung disorders, J70.4 — Drug-induced interstitial lung disorders, unspecified, K12.32 — Oral mucositis (ulcerative) due to other drugs, K52.0 — Gastroenteritis and colitis due to radiation, K52.2 — Allergic and dietetic gastroenteritis and colitis, K52.21 — Food protein-induced enterocolitis syndrome, K52.22 — Food protein-induced enteropathy, K52.29 — Other allergic and dietetic gastroenteritis and colitis, K52.3 — Indeterminate colitis, K52.81 — Eosinophilic gastritis or gastroenteritis, K52.82 — Eosinophilic colitis, K52.831 — Collagenous colitis, K52.832 — Lymphocytic colitis, K52.838 — Other microscopic colitis, +241 more

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main terms “Enteritis”, “Colitis”, “Diarrhea, diarrheal”, …; these codes share that main term but sit in a different category of the Tabular List.

K51.814 — Other ulcerative colitis with abscess (ulcerative, specified type NEC, with, complication, abscess), K51.818 — Other ulcerative colitis with other complication (ulcerative, specified type NEC, with, complication, specified complication NEC), K51.819 — Other ulcerative colitis with unspecified complications (ulcerative, specified type NEC, with, complication), K51.90 — Ulcerative colitis, unspecified, without complications (ulcerative), K51.911 — Ulcerative colitis, unspecified with rectal bleeding (ulcerative, with, complication, rectal bleeding), K51.912 — Ulcerative colitis, unspecified with intestinal obstruction (ulcerative, with, complication, obstruction), K51.913 — Ulcerative colitis, unspecified with fistula (ulcerative, with, complication, fistula), K51.914 — Ulcerative colitis, unspecified with abscess (ulcerative, with, complication, abscess), K51.918 — Ulcerative colitis, unspecified with other complication (ulcerative, with, complication, specified complication NEC), K51.919 — Ulcerative colitis, unspecified with unspecified complications (ulcerative, with, complication), K55.019 — Acute (reversible) ischemia of small intestine, extent unspecified (fulminant), K55.039 — Acute (reversible) ischemia of large intestine, extent unspecified (ischemic, acute), K55.1 — Chronic vascular disorders of intestine (ischemic, chronic), K55.9 — Vascular disorder of intestine, unspecified (ischemic), K58.0 — Irritable bowel syndrome with diarrhea (spastic, with diarrhea), K58.9 — Irritable bowel syndrome, unspecified (spastic), K59.1 — Functional diarrhea (functional), K76.82 — Hepatic encephalopathy (hepatocerebral), K90.1 — Tropical sprue (hill), K91.1 — Postgastric surgery syndromes (postvagotomy), +124 more

Lab tests where this diagnosis supports Medicare coverage (NCD)

Medicare's National Coverage Determination (NCD) program lists this diagnosis as medical justification for these lab tests.

Fecal Occult Blood Test (FOBT), Gamma-glutamyl Transferase (GGT) Test

Contextual Map

Every relationship of K52.1 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run K52.1 with these 16 related codes in Claim Check

Hierarchy

Code First (15)

Use Additional Code (15)

Clinical classification (CCSR)

MS-DRG Grouper

MDC crossing

  • MDC 06 — Diseases and Disorders of the Digestive System[MDC crossing]: “Diseases and Disorders of the Digestive System — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs. 5,748 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2027
  • MDC 15 — Newborns and Other Neonates with Conditions Originating in Perinatal Period[MDC crossing]: “Newborns and Other Neonates with Conditions Originating in Perinatal Period — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs.”— CMS MS-DRG Definitions Manual · FY2027

Index entries (18)

  • Colitis (acute) (catarrhal) (chronic) (noninfective) (hemorrhagic), drug-induced[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Colitis (acute) (catarrhal) (chronic) (noninfective) (hemorrhagic), toxic NEC[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Diarrhea, diarrheal (disease) (infantile) (inflammatory), drug-induced[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Diarrhea, diarrheal (disease) (infantile) (inflammatory), due to, drugs[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Diarrhea, diarrheal (disease) (infantile) (inflammatory), toxic[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Enteritis (acute) (diarrheal) (hemorrhagic) (noninfective), drug-induced[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Enteritis (acute) (diarrheal) (hemorrhagic) (noninfective), due to, drugs[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Enteritis (acute) (diarrheal) (hemorrhagic) (noninfective), toxic NEC[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • and 10 more

Nearest codes (17)

Change history

  • FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Deep reference

Published questions and FAQ, every source behind this page with its release and checksum, the date-of-service check and the complete change history.

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data
CMS/CDC ICD-10-CM FY2027 tabular list, index and tables, effective October 1, 2026 Release, file and checksum · Publisher’s page
Coding guidelines Official source data
ICD-10-CM Official Guidelines for Coding and Reporting (FY2027), quoted by section Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v44.0 (October 2026) Release, file and checksum · Publisher’s page
Inpatient payment groups Official source data
CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v44 Release, file and checksum · Publisher’s page
Change history and date-of-service validity Official source data
CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
Comparisons, relationships and the contextual map MedCoder structured relationship
Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
Summary and FAQ answers MedCoder explanation
Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Current data releases:ICD-10-CM FY2027 · ICD-10-PCS FY2027 · HCPCS October 2026 · MS-DRG v44 · Medicare Code Editor v44.0 · NCD code lists 2026-01 · LCD export September 20, 2026 · All releases and sources

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates · CMS coding rules

Cite this page

Reference this page in a research guide, syllabus or article. The release is included because code content changes each year.

MedCoder.ai. "K52.1 — Toxic gastroenteritis and colitis." ICD-10-CM FY2027. https://medcoder.ai/icd10/code/k52.1-toxic-gastroenteritis-and-colitis

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Toxic gastroenteritis and colitis

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027, and none are recorded for this code. Note changes are tracked from FY2027 only.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to K52.1 in its code family, with their registry titles.

View all codes in the K52 family