From my experiences as a child, I can not recall ever coming out of a revision, still having symptoms ( ie: nausea and especially a headache) unless, there was still an issue. On several occasions, I had to have 2 and sometimes 3 revisions before my issues (disconnections, occlusions, kinks etc.) were corrected. Do not let this alarm you, as this was several years ago, and these occasions were rare. Usually, a couple days post-op, i was/am raring to go! It does surprise me though, that after contacting the Drs office, they did not want to see your little boy ASAP. Like you, I also despise using the ER but, if that's what it takes to get an updated CT and x-ray, it may be worth a shot. All in all, you are mom and know your little boy best. Follow your instinct and keep digging until you get the answers he needs.