I haven't heard of this on the board before, and while it's mostly noticed in babies and children, it did say that it might not be diagnosed until adulthood.
The symptoms are severe constipation, although diarrhea may sometimes be present as well. Vomiting of bile may also occur as well, due to intestinal blockage.
http://digestive.niddk.nih.gov/ddiseases/pubs/hirschsprungs_ez/