2027 ICD-10-CM Diagnosis Code K52.1Toxic gastroenteritis and colitis

ICD-10-CM Codes›K00–K95›K50-K52›K52

ICD-10-CM K52.1
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

K52.1 is a billable ICD-10-CM diagnosis code for toxic gastroenteritis and colitis. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 393 through 395, 791, 793. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 1 closely related codes. 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
K52
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
  • 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

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to K52.1: its own notes plus those printed at block K50-K52 and Chapter 11. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From Block K50-K52 Noninfective enteritis and colitis applies to 91 codes
  • noninfective inflammatory bowel disease

Applicable To

Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.

  • Drug-induced gastroenteritis and colitis

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From Block K50-K52 Noninfective enteritis and colitis applies to 91 codes

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Chapter 11 (K00-K95) Diseases of the digestive system applies to 863 codes
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)

Code First

The underlying condition named in the note is sequenced before this code.

  • (T51-T65) to identify toxic agent

Use Additional Code

Add a second code, after this one, to fully describe the condition.

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

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

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

Colonic Diseases

Your colon, also known as the large intestine, is part of your digestive system. It's a long, hollow tube at the end of your digestive tract where your body makes and stores stool. Many disorders affect the colon's ability to work properly. Some of these include:

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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About K52.1Overview

What is the ICD-10 code for toxic gastroenteritis and colitis?

The ICD-10-CM code for toxic gastroenteritis and colitis is K52.1 (sometimes written as K521). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

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, 2026 through September 30, 2027.

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 793, 791, 394, 395, 393, with relative weights from 0.6379 to 4.2192 depending on complications. Higher weights mean higher Medicare reimbursement.

Is K52.1 a CC or MCC?

CMS lists K52.1 as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 1 closely related codes in its exclusion list.

Can K52.1 be reported with a code from K58?

Not as a rule. The Excludes1 note at block K50-K52, which applies to K52.1, lists "irritable bowel syndrome (K58.-)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).