K58.1 ICD-10-CM Code: Irritable bowel syndrome with constipation

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for K58.1 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2026Effective: October 1, 2025

Notes without a marker are published on K58.1 itself; “inherited from” names the category or block whose note applies here.

Coder workflow for K58.1

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

Before you code K58.1

1. K58.1’s title joins a condition with an associated condition or complication. Confirm each component is documented. Where the classification presumes the link through the “with” convention, only a provider statement that the conditions are unrelated defeats it. A combination code is assigned only when it fully identifies the documented conditions; a required second code for the stage, type or manifestation is still reported when the notes ask for it (Guidelines I.B.9, I.A.15).

   Guide: Combination codes →

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 associated condition or complication

Whether the associated condition the title names is documented; the “with” convention presumes some links, and a provider statement that the conditions are unrelated defeats it (Guidelines I.A.15).

Coding decision scenarios

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

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.

Indexed Clinical Terms (2)

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.

• Irritable, irritability, bowel (syndrome), with, constipation
• Syndrome, irritable, bowel, with, constipation

Official Coding Guidelines

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

Don’t confuse K58.1 with…

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

The codes most likely to be picked instead of K58.1 — 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.

• K58.9— 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 “Irritable bowel syndrome, unspecified” takes K58.9; specificity in the record moves it back here.

  Full comparison: K58.1 vs K58.9 →

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.

Verify Before Coding

• No Medicare Code Editor or MS-DRG Definitions Manual restrictions apply to this code.

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

Other codes that name K58.1 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 4 Excludes1 notes: K50 — Crohn's disease [regional enteritis] (via K58.-), K50-K52 — Noninfective enteritis and colitis (K50-K52) (via K58.-), K51 — Ulcerative colitis (via K58.-), K52 — Other and unspecified noninfective gastroenteritis and colitis (via K58.-).

These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.

Referenced by 1 Code First instruction: F54 — Psychological and behavioral factors associated with disorders or diseases classified elsewhere (via K58.-).

Each of these codes carries a Code First note naming this condition — when that code is reported, THIS code is sequenced first, ahead of it.

MS-DRG Grouper Relationships (FY2026)

Potential MS-DRG participation — not a DRG assignment.

FY2026 MS-DRG: not on the CMS CC/MCC list — as a secondary diagnosis this code does not change MS-DRG severity for that release.

Named in the grouper logic of 2 MS-DRGs: DRG 391 (MDC 06), DRG 392 (MDC 06).

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

Clinical classification (AHRQ CCSR):DIG025 — Other specified and unspecified gastrointestinal disorders (default).

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 category (Other specified and unspecified gastrointestinal disorders).

K55.1 — Chronic vascular disorders of intestine, K55.20 — Angiodysplasia of colon without hemorrhage, K55.21 — Angiodysplasia of colon with hemorrhage, K55.30 — Necrotizing enterocolitis, unspecified, K55.31 — Stage 1 necrotizing enterocolitis, K55.32 — Stage 2 necrotizing enterocolitis, K55.33 — Stage 3 necrotizing enterocolitis, K55.8 — Other vascular disorders of intestine, K55.9 — Vascular disorder of intestine, unspecified, K58.0 — Irritable bowel syndrome with diarrhea, K58.2 — Mixed irritable bowel syndrome, K58.8 — Other irritable bowel syndrome, K58.9 — Irritable bowel syndrome, unspecified, K59.00 — Constipation, unspecified, K59.01 — Slow transit constipation, K59.02 — Outlet dysfunction constipation, K59.03 — Drug induced constipation, K59.04 — Chronic idiopathic constipation, K59.09 — Other constipation, K59.1 — Functional diarrhea, +64 more

Same Index main term, other category

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

F45.8 — Other somatoform disorders (heart), G90.89 — Other disorders of autonomic nervous system (sympathetic), K31.89 — Other diseases of stomach and duodenum (stomach), K59.89 — Other specified functional intestinal disorders (ileum), N32.89 — Other specified disorders of bladder (bladder), N36.8 — Other specified disorders of urethra (urethra), P91.3 — Neonatal cerebral irritability (cerebral, in newborn), R45.4 — Irritability and anger, R68.12 — Fussy infant (baby) (infant)

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), Thyroid Stimulating Hormone (TSH)

Contextual Map

Every relationship of K58.1 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 K58.1 with these 5 related codes in Claim Check

Hierarchy

• K00-K95 — Chapter 11: Diseases of the Digestive System (K00-K95) (K00-K95)[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• K55-K64 — Other diseases of intestines[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026

Referenced by Excludes1 notes

• K50 — Crohn's disease [regional enteritis][Excludes1](via K58.-): “irritable bowel syndrome (K58.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• K50-K52 — Noninfective enteritis and colitis (K50-K52)[Excludes1](via K58.-): “irritable bowel syndrome (K58.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• K51 — Ulcerative colitis[Excludes1](via K58.-): “irritable bowel syndrome (K58.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• K52 — Other and unspecified noninfective gastroenteritis and colitis[Excludes1](via K58.-): “irritable bowel syndrome (K58.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Referenced by Code First instructions

• F54 — Psychological and behavioral factors associated with disorders or diseases classified elsewhere[Code First](via K58.-): “mucous colitis (K58.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Clinical classification (CCSR)

• DIG025 — Other specified and unspecified gastrointestinal disorders[CCSR]— AHRQ CCSR for ICD-10-CM Diagnoses (HCUP)

MS-DRG Grouper

• DRG 391 — ESOPHAGITIS, GASTROENTERITIS AND MISCELLANEOUS DIGESTIVE DISORDERS WITH MCC[MS-DRG]: “ESOPHAGITIS, GASTROENTERITIS AND MISCELLANEOUS DIGESTIVE DISORDERS WITH MCC (MDC 06)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
• DRG 392 — ESOPHAGITIS, GASTROENTERITIS AND MISCELLANEOUS DIGESTIVE DISORDERS WITHOUT MCC[MS-DRG]: “ESOPHAGITIS, GASTROENTERITIS AND MISCELLANEOUS DIGESTIVE DISORDERS WITHOUT MCC (MDC 06)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026

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. 5,744 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2026

Index entries

• Irritable, irritability, bowel (syndrome), with, constipation[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
• Syndrome, irritable, bowel, with, constipation[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026

Nearest codes

• K58 — Irritable bowel syndrome[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• K58.0 — Irritable bowel syndrome with diarrhea[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• K58.2 — Mixed irritable bowel syndrome[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• K58.8 — Other irritable bowel syndrome[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• K58.9 — Irritable bowel syndrome, unspecified[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026

Change history

• FY2017 — Added to the code set[Change history]— CMS release files (code change ledger) · icd10cm-fy2017

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 FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page

Coding guidelines Official source data

ICD-10-CM Official Guidelines for Coding and Reporting (FY2026), quoted by section Release, file and checksum · Publisher’s page

Claim edits Official source data

CMS Definitions of Medicare Code Edits — v43.1 (April 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 — v43 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.

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

Nearest Codes in This Family

Official ICD-10-CM classifications closest to K58.1 in its code family, with their registry titles.

• K58 — Irritable bowel syndrome
• K58.0 — Irritable bowel syndrome with diarrhea
• K58.2 — Mixed irritable bowel syndrome
• K58.8 — Other irritable bowel syndrome
• K58.9 — Irritable bowel syndrome, unspecified

View all codes in the K58 family