|  | 
   | 531 Gastric ulcer 
Includes: ulcer (peptic): 
prepyloric 
pylorus 
stomach 
Use additional E code to identify drug, if drug-induced 
Excludes: peptic ulcer NOS (533.0-533.9) 
The following fifth-digit subclassification is for use with category 531: 
0 without mention of obstruction 
1 with obstruction  | 
    | 531.0 Acute with hemorrhage 
[0-1]  | 
    | 531.1 Acute with perforation 
[0-1]  | 
    | 531.2 Acute with hemorrhage and perforation 
[0-1]  | 
    | 531.3 Acute without mention of hemorrhage or perforation 
[0-1]  | 
    | 531.4 Chronic or unspecified with hemorrhage 
[0-1]  | 
    | 531.5 Chronic or unspecified with perforation 
[0-1]  | 
    | 531.6 Chronic or unspecified with hemorrhage and perforation 
[0-1]  | 
    | 531.7 Chronic without mention of hemorrhage or perforation 
[0-1]  | 
    | 531.9 Unspecified as acute or chronic, without mention of hemorrhage or perforation 
[0-1]  |