Other diseases of stomach and duodenum (K31) ICD-10-CM
The K31 code range covers other diseases of stomach and duodenum with 31 ICD-10-CM diagnosis codes. 25 of them are billable and valid for claim submission in fiscal year 2026, and the category headers group them but cannot themselves be billed.
Includes
This note appears immediately under a three character code title to further define, or give examples of, the content of the category.
- functional disorders of stomach
Type 2 Excludes
A type 2 excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.
Codes in the K31 Range 31 codes · 25 billable
- K31 Other diseases of stomach and duodenumNon-billable
- K31.0 Acute dilatation of stomach
- K31.1 Adult hypertrophic pyloric stenosis
- K31.2 Hourglass stricture and stenosis of stomach
- K31.3 Pylorospasm, not elsewhere classified
- K31.4 Gastric diverticulum
- K31.5 Obstruction of duodenum
- K31.6 Fistula of stomach and duodenum
- K31.7 Polyp of stomach and duodenum
- K31.8 Other specified diseases of stomach and duodenumNon-billable
- K31.81 Angiodysplasia of stomach and duodenumNon-billable
- K31.811 Angiodysplasia of stomach and duodenum with bleeding
- K31.819 Angiodysplasia of stomach and duodenum without bleeding
- K31.82 Dieulafoy lesion (hemorrhagic) of stomach and duodenum
- K31.83 Achlorhydria
- K31.84 Gastroparesis
- K31.89 Other diseases of stomach and duodenum
- K31.9 Disease of stomach and duodenum, unspecified
- K31.A Gastric intestinal metaplasiaNon-billable
- K31.A0 Gastric intestinal metaplasia, unspecified
- K31.A1 Gastric intestinal metaplasia without dysplasiaNon-billable
- K31.A11 Gastric intestinal metaplasia without dysplasia, involving the antrum
- K31.A12 Gastric intestinal metaplasia without dysplasia, involving the body (corpus)
- K31.A13 Gastric intestinal metaplasia without dysplasia, involving the fundus
- K31.A14 Gastric intestinal metaplasia without dysplasia, involving the cardia
- K31.A15 Gastric intestinal metaplasia without dysplasia, involving multiple sites
- K31.A19 Gastric intestinal metaplasia without dysplasia, unspecified site
- K31.A2 Gastric intestinal metaplasia with dysplasiaNon-billable
- K31.A21 Gastric intestinal metaplasia with low grade dysplasia
- K31.A22 Gastric intestinal metaplasia with high grade dysplasia
- K31.A29 Gastric intestinal metaplasia with dysplasia, unspecified
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the K31 range.
Achlorhydria
A lack of HYDROCHLORIC ACID in GASTRIC JUICE despite stimulation of gastric secretion.
Gastric Fistula
Abnormal passage communicating with the STOMACH.
Gastroparesis
Chronic delayed gastric emptying. Gastroparesis may be caused by motor dysfunction or paralysis of STOMACH muscles or may be associated with other systemic diseases such as DIABETES MELLITUS.
Hypertrophy
General increase in bulk of a part or organ due to CELL ENLARGEMENT and accumulation of FLUIDS AND SECRETIONS, not due to tumor formation, nor to an increase in the number of cells (HYPERPLASIA).
Intestinal Volvulus
A twisting in the intestine (INTESTINES) that can cause INTESTINAL OBSTRUCTION.
Pyloric Stenosis
Narrowing of the pyloric canal with varied etiology. A common form is due to muscle hypertrophy (PYLORIC STENOSIS, HYPERTROPHIC) seen in infants.
Pyloric Stenosis, Hypertrophic
Narrowing of the pyloric canal due to HYPERTROPHY of the surrounding circular muscle. It is usually seen in infants or young children.
Stomach
An organ of digestion situated in the left upper quadrant of the abdomen between the termination of the ESOPHAGUS and the beginning of the DUODENUM.
About the K31 Code Range
This section, identified by K31 in the ICD-10 coding system, covers a variety of other diseases of the stomach and duodenum not classified elsewhere. These codes are used to document conditions such as acute stomach dilation, strictures, fistulas, polyps, and motility disorders, helping medical professionals accurately classify rare or complex gastrointestinal diagnoses.
The ICD-10 code for acute dilatation of stomach (K31.0) includes cases called Bouchard's disease. Adult hypertrophic pyloric stenosis (K31.1) covers acquired narrowing or obstruction of the pylorus, also known by terms like pyloric obstruction or acquired pyloric stricture. Codes such as K31.4 and K31.5 are assigned for gastric diverticulum and duodenal obstruction, respectively, the latter encompassing various duodenal ulcer complications. The section also includes angiodysplasia with or without bleeding (K31.81 series), a vascular abnormality sometimes resulting in gastrointestinal hemorrhage. Additionally, gastroparesis (K31.84) is coded here, describing delayed stomach emptying or gastric motor dysfunction. For polyps in the stomach and duodenum, K31.7 is used, covering benign growths like fundic gland polyposis and inflammatory fibroid polyps. The section extends to diseases like gastric intestinal metaplasia (K31.A series), from unspecified to those with dysplasia, important in assessing precancerous stomach changes.
Questions About This Page
How many billable codes are in the K31 range?
Of the 31 codes in this range, 25 are billable and valid for claim submission from October 1, 2025 through September 30, 2026. Category header codes group them but cannot be reported on claims.
What does the K31 range classify?
The range classifies other diseases of stomach and duodenum. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.
