What is the name of your state (only U.S. law)? Missouri

I am being sued for medical debt that i owe. I have a court date tomorrow. I did not file a written response because I assumed all of the debt was mine and that i owed it. I found out today that part of that debt is from an unpaid worker's compensation claim (approved and recognized by my employer). Do i still have time to file an answer? Can i just give my answer if i choose to appear? Will i have recourse if a default judgement is granted? Also, can i get in trouble for not appearing (other than a default judgment). This would be the first date i am to meet in a court for this debt and the summons says if i don't appear then it will be a default judgement (nothing about contempt?).