ICD-10-CM > Z00-Z99 > Z00-Z13 > Z13 > Z13.8 > Z13.81 Z13.81 Encounter for screening for digestive system disorders Non-Billable/Non-Specific Codes Z13.810Encounter for screening for upper gastrointestinal disorderZ13.811Encounter for screening for lower gastrointestinal disorderZ13.818Encounter for screening for other digestive system disorders