ICD-10 code for intestinal upset

The ICD-10-CM code for intestinal upset is K59.9 (Functional intestinal disorder, unspecified). The official index lists 1 more specific code, so check the documentation for details such as type, cause, site or severity before settling on K59.9.

Within K59, choose K59.9 (Functional intestinal disorder, unspecified) only when documentation doesn't support a more specific option: constipation (K59.0), functional diarrhea (K59.1), neurogenic bowel, not elsewhere classified (K59.2), megacolon, not elsewhere classified (K59.3), anal spasm (K59.4) and other specified functional intestinal disorders (K59.8).

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 391 (Esophagitis, Gastroenteritis and Miscellaneous Digestive Disorders with MCC, relative weight 1.2392) and DRG 392 (Esophagitis, Gastroenteritis and Miscellaneous Digestive Disorders without MCC, relative weight 0.7645), in MDC 06 (Diseases and Disorders of the Digestive System), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.