K31 Other diseases of stomach and duodenum

Category / Non-billable header 31 subcodes

Block: Diseases of esophagus, stomach and duodenum (K20-K31)

Includes

  • functional disorders of stomach

Excludes 2 (not included here)

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

Subcodes

Subcodes are listed below for reference. Detail pages are not available for chapters 11–22.

Code Description Billable
K31..0 Acute dilatation of stomach Yes
K31..1 Adult hypertrophic pyloric stenosis Yes
K31..B Hypertrophic pyloric stenosis, in childhood Yes
K31..2 Hourglass stricture and stenosis of stomach Yes
K31..3 Pylorospasm, not elsewhere classified Yes
K31..4 Gastric diverticulum Yes
K31..5 Obstruction of duodenum Yes
K31..6 Fistula of stomach and duodenum Yes
K31..7 Polyp of stomach and duodenum Yes
K31..8 Other specified diseases of stomach and duodenum No
K31..81 Angiodysplasia of stomach and duodenum No
K31..811 Angiodysplasia of stomach and duodenum with bleeding Yes
K31..819 Angiodysplasia of stomach and duodenum without bleeding Yes
K31..82 Dieulafoy lesion (hemorrhagic) of stomach and duodenum Yes
K31..83 Achlorhydria Yes
K31..84 Gastroparesis Yes
K31..89 Other diseases of stomach and duodenum Yes
K31..9 Disease of stomach and duodenum, unspecified Yes
K31..A Gastric intestinal metaplasia No
K31..A0 Gastric intestinal metaplasia, unspecified Yes
K31..A1 Gastric intestinal metaplasia without dysplasia No
K31..A11 Gastric intestinal metaplasia without dysplasia, involving the antrum Yes
K31..A12 Gastric intestinal metaplasia without dysplasia, involving the body (corpus) Yes
K31..A13 Gastric intestinal metaplasia without dysplasia, involving the fundus Yes
K31..A14 Gastric intestinal metaplasia without dysplasia, involving the cardia Yes
K31..A15 Gastric intestinal metaplasia without dysplasia, involving multiple sites Yes
K31..A19 Gastric intestinal metaplasia without dysplasia, unspecified site Yes
K31..A2 Gastric intestinal metaplasia with dysplasia No
K31..A21 Gastric intestinal metaplasia with low grade dysplasia Yes
K31..A22 Gastric intestinal metaplasia with high grade dysplasia Yes
K31..A29 Gastric intestinal metaplasia with dysplasia, unspecified Yes

Last reviewed: September 2026