2026 ICD-10-CM Diagnosis Code K52.1Toxic gastroenteritis and colitis

ICD-10-CM CodesK00–K95K50-K52K52

ICD-10-CM K52.1
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

K52.1 is a billable ICD-10-CM diagnosis code for toxic gastroenteritis and colitis. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 393 through 395. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Drug induced or toxic related condition and Noninfectious gastroenteritis.

Code Identity

ICD-10-CM Code
K52.1
Billable Status
Yes — Valid for Submission
Code Describes
Toxic gastroenteritis and colitis
Short Description
Toxic gastroenteritis and colitis
Same as the full description in the CMS dataset.
Parent Code
Other and unspecified noninfective gastroenteritis and colitis

Code Classification

ChapterK00–K95Diseases of the digestive system
SectionK50-K52Noninfective enteritis and colitis
CategoryK52Other and unspecified noninfective gastroenteritis and colitis
This CodeK52.1Toxic gastroenteritis and colitis

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Antibiotic enterocolitis
  • Antibiotic-associated diarrhea
  • Chemical colitis
  • Diarrhea caused by alcohol intake
  • Diarrhea caused by drug
  • Diarrhea caused by ingestion of unabsorbable substances
  • Diarrhea due to harmful pattern of laxative use
  • Diarrheic shellfish poisoning
  • Drug-induced colitis
  • Drug-induced enteritis of intestine
  • Gastritis medicamentosa
  • Gastroenteritis caused by drug
  • Immune checkpoint inhibitor therapy induced enterocolitis
  • Malabsorption caused by drug
  • Non-infective diarrhea
  • Noninfective enteritis and colitis
  • Non-steroidal anti-inflammatory drug-induced colitis
  • Non-steroidal anti-inflammatory drug-induced enteropathy
  • Osmotic diarrhea
  • Soap colitis
  • Toxic effect from eating shellfish
  • Toxic enteritis of small intestine
  • Toxic enteritis of small intestine caused by drug
  • Toxic gastroenteritis

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Drug-induced gastroenteritis and colitis

Code First

Use Additional Code

  • code for adverse effect, if applicable, to identify drug T36 T50

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Colitis(acute) (catarrhal) (chronic) (noninfective) (hemorrhagic)
      • drug-induced
    • Colitis(acute) (catarrhal) (chronic) (noninfective) (hemorrhagic)
      • toxic NEC
    • Diarrhea, diarrheal(disease) (infantile) (inflammatory)
      • drug-induced
    • Diarrhea, diarrheal(disease) (infantile) (inflammatory)
      • due to
        • drugs
    • Diarrhea, diarrheal(disease) (infantile) (inflammatory)
      • toxic
    • Enteritis(acute) (diarrheal) (hemorrhagic) (noninfective)
      • drug-induced
    • Enteritis(acute) (diarrheal) (hemorrhagic) (noninfective)
      • due to
        • drugs
    • Enteritis(acute) (diarrheal) (hemorrhagic) (noninfective)
      • toxic NEC
    • Gastroenteritis(acute) (chronic) (noninfectious)
      • drug-induced
    • Gastroenteritis(acute) (chronic) (noninfectious)
      • due to
        • drugs
    • Gastroenteritis(acute) (chronic) (noninfectious)
      • toxic
    • Intoxication
      • alimentary canal
    • Intoxication
      • enteric
    • Intoxication
      • gastrointestinal
    • Toxemia
      • gastrointestinal
    • Toxemia
      • intestinal
    • Toxemia
      • small intestine
    • Toxinfection, gastrointestinal

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR INJ030
Drug induced or toxic related condition
Default principal diagnosis: inpatient No · outpatient No
CCSR DIG022
Noninfectious gastroenteritis
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Gastroenteritis

Gastroenteritis is an inflammation of the lining of the stomach and intestines. The main symptoms include vomiting and diarrhea. It is usually not serious in healthy people, but it can sometimes lead to dehydration or cause severe symptoms.

The full article covers:

  • What is gastroenteritis?
  • What causes gastroenteritis?
  • What are the symptoms of gastroenteritis?
  • How is gastroenteritis diagnosed?
  • What are the treatments for gastroenteritis?
  • Can gastroenteritis be prevented?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert K52.1 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
558.2 Toxic gastroenteritis
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About K52.1Overview

Is K52.1 a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report toxic gastroenteritis and colitis on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does K52.1 group to?

When toxic gastroenteritis and colitis is the principal diagnosis on an inpatient stay, it groups to MS-DRG 393, 394, 395, with relative weights from 0.6490 to 1.5993 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of K52.1?

Under the General Equivalence Mappings, toxic gastroenteritis and colitis converts to ICD-9-CM 558.2 (toxic gastroenteritis). The mapping is a direct match.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.