In the ICD for the dx, if you look in the index under "Incarceration, incarcerated" and "omentum (by hernia)", it says "(see also Hernia, by site, with obstruction)", so it's certainly acceptable to use the incarcerated dx code, & by extension, the incarcerated procedure code. If the doc didn't bother to mention it except to say some incarcerated omentum was reduced, tho, it was probably pretty minimal, and he/she may not wish to bill it out as an incarcerated repair.