Suggest Remedy For Chronic Constipation With White Specks In Stools

For the past 6 months, I have been experiencing constipation which seems to now be chronic. I have increased my water intake to 8-10 glasses/day, take a fiber supplement like Metamucil 3 times/day, have increased my daily intake of fruits and nuts, bran flakes for breakfast and other suggested diet remedies. I still get a hard stool in small chunks about the size of my little finger up to the first joint. I have tried taking stool softeners, but they do not seem to help. Most bowel movements are a hard push. Then still, once or twice a week, I will have to take a laxative. Also, recently, I have noticed small white specks in my stool. Almost 2 years ago, I had radiation treatment for prostrate cancer. I do not see any blood in my stool. Am I in trouble? Help!!