K31.89

Other diseases of stomach and duodenum

Billable FY2026 2025-10-01 → 2026-09-30

Exclusions 11 never code together

K31code

Excludes2

diabetic gastroparesis (E08.43, E09.43, E10.43, E11.43, E13.43)E08.43 E09.43 E10.43 E11.43 E13.43
diverticulum of duodenum (K57.00-K57.13)K57.00-K57.13

K20-K31block

Excludes2

hiatus hernia (K44.-)K44.-

K00-K95chapter

Excludes2

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

Excludes2 — not included here, but the patient may have both. Code both when documented.

Instructional notes 1

K31code

Includes

functional disorders of stomach

Index entries leading here 59

Achylia gastrica K31.89
Deformity Q89.9
- duodenum (congenital) Q43.9
  - acquired K31.89
- stomach (congenital) Q40.3
  - acquired K31.89
- pylorus (congenital) Q40.3
  - acquired K31.89
- duodenal bulb K31.89
Spasm (s) , spastic, spasticity R25.2
- pylorus NEC K31.3
  - adult hypertrophic K31.89
- gastrointestinal (tract) K31.89
- stomach K31.89
Atonia, atony, atonic
- stomach K31.89
Calculus, calculi, calculous
- stomach K31.89
Indigestion (acid) (bilious) (functional) K30
- catarrhal K31.89
Congestion, congestive
- duodenum K31.89
- stomach K31.89
Gastropathy K31.9
- congestive portal (see also, Hypertension, portal) K31.89
- specified NEC K31.89
- portal hypertensive (see also, Hypertension, portal) K31.89
Contraction (s) , contracture, contracted
- hourglass
  - stomach K31.89
- stomach K31.89
  - hourglass K31.89
Degeneration, degenerative
- stomach K31.89
Dilatation
- stomach K31.89
Disease, diseased — see also Syndrome
- stomach K31.9
  - specified NEC K31.89
- duodenum K31.9
  - specified NEC K31.89
- Rossbach's (hyperchlorhydria) K31.89
Distension, distention
- stomach K31.89
Syndrome — see also Disease
- dumping (postgastrectomy) K91.1
  - nonsurgical K31.89
Rupture, ruptured
- duodenal stump K31.89
- stomach (nontraumatic) (spontaneous) K31.89
Hypertrophy, hypertrophic
- duodenum K31.89
- stomach K31.89
Dysfunction
- stomach K31.89
Engorgement
- stomach K31.89
Fish hook stomach K31.89
Vomiting R11.10
- functional K31.89
Retention — see also Retained
- gastric K31.89
Ptosis — see also Blepharoptosis
- gastric K31.89
- stomach K31.89
Irritation
- gastric K31.89
- stomach K31.89
Hypersecretion
- gastric K31.89
Prolapse, prolapsed
- gastric (mucosa) K31.89
- stomach K31.89
Malfunction — see also Dysfunction
- gastroenteric K31.89
Hyperactive, hyperactivity F90.9
- gastrointestinal K31.89
- stomach K31.89
Hypomotility
- gastrointestinal (tract) K31.89
- stomach K31.89
Gastroliths K31.89
Gastromalacia K31.89
Hypertension, hypertensive (accelerated) (benign) (essential) (idiopathic) (malignant) (systemic) I10
- portal (due to chronic liver disease) (idiopathic) K76.6
  - gastropathy K31.89
Gastroptosis K31.89
Gastrospasm (neurogenic) (reflex) K31.89
Gastrostenosis K31.89
Gastrosuccorrhea (continuous) (intermittent) K31.89
Hourglass (contracture) — see also Contraction, hourglass
- stomach K31.89
Hyperacidity (gastric) K31.89
Hyperchlorhydria K31.89
Hyperemia (acute) (passive) R68.89
- stomach K31.89
Hypermobility, hypermotility
- stomach K31.89
Hypertony, hypertonia, hypertonicity
- stomach K31.89
Hypoacidity, gastric K31.89
Hypochlorhydria K31.89
Inertia
- stomach K31.89
Insufficiency, insufficient
- pyloric K31.89
Irritable, irritability R45.4
- stomach K31.89
Malposition
- stomach K31.89
Megalogastria (acquired) K31.89
Necrosis, necrotic (ischemic) — see also Gangrene
- stomach K31.89
Obstruction, obstructed, obstructive
- stomach NEC K31.89
Redundant, redundancy
- pylorus K31.89
- stomach K31.89
Reichmann's disease or syndrome K31.89
Rossbach's disease K31.89
Sclerosis, sclerotic
- stomach K31.89
Softening
- stomach K31.89
Stricture — see also Stenosis
- stomach K31.89
Volvulus (bowel) (colon) (intestine) K56.2
- stomach (due to absence of gastrocolic ligament) K31.89
Subacidity, gastric K31.89
Tachygastria K31.89

Alongside this code 4 same parent — K31.8

K31.81 Angiodysplasia of stomach and duodenum category K31.82 Dieulafoy lesion (hemorrhagic) of stomach and duodenum K31.83 Achlorhydria K31.84 Gastroparesis

Additional references

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Risk adjustment

Maps to no condition category in any loaded model.

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This code

Billable: yes
Code set: FY2026
Parent: K31.8
Block: K20-K31
Siblings: 4

Present FY2024–FY2027.