My daughter had a problem when she was much younger. It turned out she had Celiac disease. There is the Encopresis Center in Edmonds, Washington. Their url is http://encopresistreatment.com/. Also, I recommend Dr. Cheryl Woods, Naturopath in Lynnwood at the Trinity Health Center. She is absolutely TOPS in treating digestive problems. Probably finding out what's wrong from a Naturopath is the best way to go, because the Encopresis center never became aware of the fact that my daughter had Celiac disease, but the Naturopath - another great one is Dr. Jodi Berg, on Colby in Everett. She is amazing. She diagnosed my daughter as Celiac. She was so bad, it was destroying her mind. Fortunately we got her off wheat before she would have become autistic from the poisons her body was throwing into her blood as a result of this illness.
Also, I would talk to a nutritionist. I noticed that the Encopresis center mainly centered on softening the stool. However, food allergies can be causing the symptoms you are describing. Food allergies are best found out by going to a naturopath.