| ICD-10 Code | Description |
| 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 |
| K31.811 | 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.A0 | Gastric intestinal metaplasia, unspecified |
| 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.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 |
