Infectious Gastroenteritis ICD-10-CM codes

A09 (infectious gastroenteritis and colitis, unspecified) is assigned when the provider documents gastroenteritis as infectious or presumed infectious but the organism is unknown. When a virus is identified, use A08: A08.0 rotaviral enteritis, A08.11 norovirus (Norwalk agent), A08.2 adenoviral enteritis, and A08.4 for viral gastroenteritis with no virus specified. Bacterial gastroenteritis is coded to the organism in A02 to A05 (for example A02.0 Salmonella enteritis, A04.5 Campylobacter), not to A09.

Documentation of gastroenteritis alone, with no mention of an infectious cause, indexes to K52.9 (noninfective gastroenteritis and colitis, unspecified). This is the most common error in this area. Query or read the note carefully: terms such as stomach flu, viral gastroenteritis, or acute infectious diarrhea support a chapter 1 code, while gastroenteritis NOS belongs in chapter 11.

Diarrhea, vomiting, and abdominal cramping are integral to gastroenteritis and are not coded separately. Dehydration (E86.0) and electrolyte disturbances (E87.-) are coded in addition when documented, and dehydration may be sequenced first when it is the reason for admission and the only condition treated. Travelers' diarrhea indexes to A09.