Douglas A. Drossman, MD: When it becomes more chronic, we need to evaluate it and make sure there's nothing else causing that. This might involve a colonoscopy or some blood tests. Being sure that there are no medications that they are taking that could be treated. And so once that's in place, if the constipation becomes more severe, we start to look at various types of treatments. The kinds of things that we've used could be PEG solution, which increases the fluid content of the bowel and moves things along. We've used something called lupiprostone, uh which activates the chloride secretion in the bowel and makes the bowel more liquid and activates it. And there are other types of agents that could be used.