Yes, the effects of bulimia can usually be reversed if a person seeks treatment and overcomes the disease. However, there are some effects that may require medical treatments to reverse. For instance, if the patient has suffered erosion on the teeth that caused discoloration or tooth decay, their dentist may need to add fillings or possibly cap the teeth to make them appear normal again.
Depending on the age of the patient, there may be some effects that aren't reversible, such as the reduction of calcium that can cause brittle bones as the person grows older. Also, malnutrition and high doses of sugar can cause a person suffering from bulimia to develop diabetes mellitus type 2. These might be issues that the person cannot reverse and needs treatment for on an ongoing basis.