Usually, nothing can be done to prevent a bowel obstruction. A person who has had an obstruction from hard stools may be given stool softeners to prevent a repeat obstruction.
The bowel may develop a tear, called an intestinal perforation, or have its blood supply cut off. A lack of blood supply to the bowel can cause the tissue to die. A condition know as gangrene may develop as a result. These are both serious complications that may result in severe infections and death.
A bowel obstruction is not contagious, and poses no risks to others.