- Gastrectasis, gastrectasia 536.1
- Gastric - see condition
- Gastrinoma (M8153/1)
- Gastritis 535.5
- Gastrocarcinoma (M8010/3) 151.9
- Gastrocolic - see condition
- Gastrocolitis - see Enteritis
- Gastrodisciasis 121.8
- Gastroduodenitis (see also Gastritis) 535.5
- Gastrodynia 536.8
- Gastroenteritis (acute) (catarrhal) (congestive) (hemorrhagic) (noninfectious) (see also Enteritis) 558.9
- Gastroenterocolitis - see Enteritis
- Gastroenteropathy, protein-losing 579.8
- Gastroenteroptosis 569.89
- Gastroesophageal laceration-hemorrhage syndrome 530.7
- Gastroesophagitis 530.19
- Gastrohepatitis (see also Gastritis) 535.5
- Gastrointestinal - see condition
- Gastrojejunal - see condition
- Gastrojejunitis (see also Gastritis) 535.5
- Gastrojejunocolic - see condition
- Gastroliths 537.89