Phosphorus is a mineral which is important for every cell in the body. Sodium phosphate and sodium biphosphate are just some forms of phosphorus usually used to clean the bowel before intestinal procedures (x-rays, endoscopy) and surgery. They are also used to treat constipation, to help relieve impacted bowels and for general care after surgery. They may also be used for some other purposes. You should not use them without first talking to your doctor, especially if you have an electrolyte imbalance, are on a sodium restricted diet; have kidney disease or congestive heart failure. If you have any of these conditions and use sodium biphosphate or sodium phosphate you may experience life-threatening toxicity. Much more powerful natural laxative is flaxseed. If taken properly and regularly it will solve your problem. I have advised many people to do so and do not know anybody who hasn’t been relieved of this problem using flaxseed.