K31.6 Fistula of stomach and duodenum

Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis.

Applicable to

• Gastrocolic fistula
• Gastrojejunocolic fistula

Code also

• , if applicable, disruption of internal operation (surgical) wound (T81.32-)

Applies from K31 Other diseases of stomach and duodenum

Includes

• functional disorders of stomach

Excludes2 (not included here)

• diabetic gastroparesis (E08.43, E09.43, E10.43, E11.43, E13.43)
• diverticulum of duodenum (K57.00-K57.13)

MS-DRG index

Defines the logic of DRG(s) 391-392 in MDC 06.

Approximate ICD-9-CM (GEMs)

• 537.4 Fistula of stomach or duodenum

Code annotations containing back-references to K31.6

Back-references to K31.6

• Type 1 Excludes: K63.2 Fistula of intestine ("fistula of duodenum (K31.6)")

Back-references to K31

• Type 2 Excludes: K59 Other functional intestinal disorders ("functional disorders of stomach (K31.-)")

Diagnosis Index entries for K31.6

• Fistula (cutaneous) › duodenum
• Fistula (cutaneous) › gastric
• Fistula (cutaneous) › gastrocolic
• Fistula (cutaneous) › gastroenterocolic
• Fistula (cutaneous) › gastroesophageal
• Fistula (cutaneous) › gastrojejunal
• Fistula (cutaneous) › gastrojejunocolic
• Fistula (cutaneous) › stomach

Nearby codes

• 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 (this code)
• K31.7 Polyp of stomach and duodenum
• K31.8 Other specified diseases of stomach and duodenum
• K31.81 Angiodysplasia of stomach and duodenum
• K31.811 Angiodysplasia of stomach and duodenum with bleeding
• K31.819 Angiodysplasia of stomach and duodenum without bleeding