Hi. If you prove that this is appendix damage due to car accident I d like you to send me all infos because i wanna public this as case study:)) There are plenty of organs which can be damaged and incidence of appendix injury is probably 0.000001%. So you should think of the most common disorders first. Did you check(x-ray) pelvic bones and lumbal spine. Pain can be felt due to even small fractures. Just dont worry, I think its nothing but... I am an author of the book Abdominal trauma-for medical students and I want to inform you that abdominal injuries can have very unspecific clinical presentation. It is not necessary to have symptoms right after the trauma, even more then 5 days can pass.Seatbelt can cause variety of injuries especially of the spleen and small intestines, but its very hard for hernia to develop. The most dangerous disorders that can occur are intraabdominal bleeding and hollow organs perforation followed by infection and sepsis. You obviously dont have bleeding, but organ injuries and abdominal infection should be ruled out. The best way to do it is ultrasonography or CT scan. Check your red blood count and inflammatory parameters.