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  5. Gastritis and duodenitis (K29)

Gastritis and duodenitis (K29)

The ICD-10 code section K29 covers a range of conditions related to inflammation of the stomach lining (gastritis) and the first part of the small intestine (duodenitis). These codes help specify the exact type, cause, and whether bleeding is involved, guiding accurate diagnosis and treatment.

This section includes acute gastritis (K29.0), which can be erosive or superficial and may or may not involve bleeding; alcoholic gastritis (K29.2), linked to alcohol consumption and sometimes causing bleeding; and chronic forms such as superficial, atrophic, and unspecified gastritis, each with distinct characteristics and potential complications. Terms like erosive gastritis, acute neutrophilic gastritis, and Helicobacter pylori-associated gastritis correspond to specific codes here, helping coders pinpoint precise diagnoses. The section also covers duodenitis (K29.8), including infectious and immune-related causes, with codes distinguishing bleeding status. The unspecified gastritis and gastroduodenitis codes (K29.7, K29.9) are used when the inflammation’s origin or type is unclear. Using these detailed codes ensures accurate medical records and appropriate clinical care.

Instructional Notations

Type 1 Excludes

A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.

  • eosinophilic gastritis or gastroenteritis K52.81
  • Zollinger-Ellison syndrome E16.4

Clinical Terms

The following clinical terms provide additional context, helping users better understand the clinical background and common associations for each diagnosis listed in this section. Including related terms alongside ICD-10-CM codes supports coders, billers, and healthcare professionals in improving accuracy, enhancing documentation, and facilitating research or patient education.

Ancylostoma

A genus of nematode intestinal parasites that consists of several species. A. duodenale is the common hookworm in humans. A. braziliense, A. ceylonicum, and A. caninum occur primarily in cats and dogs, but all have been known to occur in humans.

Ancylostomiasis

Infection of humans or animals with hookworms of the genus ANCYLOSTOMA. Characteristics include anemia, dyspepsia, eosinophilia, and abdominal swelling.

Duodenitis

Inflammation of the DUODENUM section of the small intestine (INTESTINE, SMALL). Erosive duodenitis may cause bleeding in the UPPER GI TRACT and PEPTIC ULCER.

Gastric Mucosa

Lining of the STOMACH, consisting of an inner EPITHELIUM, a middle LAMINA PROPRIA, and an outer MUSCULARIS MUCOSAE. The surface cells produce MUCUS that protects the stomach from attack by digestive acid and enzymes. When the epithelium invaginates into the LAMINA PROPRIA at various region of the stomach (CARDIA; GASTRIC FUNDUS; and PYLORUS), different tubular gastric glands are formed. These glands consist of cells that secrete mucus, enzymes, HYDROCHLORIC ACID, or hormones.

Gastritis

Inflammation of the GASTRIC MUCOSA, a lesion observed in a number of unrelated disorders.

Gastritis, Atrophic

GASTRITIS with atrophy of the GASTRIC MUCOSA, the GASTRIC PARIETAL CELLS, and the mucosal glands leading to ACHLORHYDRIA. Atrophic gastritis usually progresses from chronic gastritis.

Gastritis, Hypertrophic

GASTRITIS with HYPERTROPHY of the GASTRIC MUCOSA. It is characterized by giant gastric folds, diminished acid secretion, excessive MUCUS secretion, and HYPOPROTEINEMIA. Symptoms include VOMITING; DIARRHEA; and WEIGHT LOSS.