Just for info, I asked Dr. Ron on a different board and got this responce (mine is doing the same thing):
The structure extending from the mouth of the Linckia is the cardiac stomach and possibly part to the pyloric stomach. It is normal for some of this structure to protrude from the mouth, but it is not normal for this much to be extended. It is possible that something is stressing the star and causing stomach expulsion or it is possible that some fish or other animal actually attacked the star and pulled the stomach out like this.
If the star can retract the stomach, it will die. However, it may take it several days to get it back in.
FYI, HTH in the future.