Stacie,
A lot of medical sources do list frequent urination, along with frequent bowel movements, as a symptom of Grave's Disease. Some list it as a symptom of both hyperthyroidism and hypothyroidism. It can be a symptom of other problems as well, such as diabetes, kidney and liver problems.
I replied on your post about your elevated ALP and the frequent urination symptom adds to the importance of discussing this with your Dr., he may already know the answer and needs to inform you. Your PTU could possibly be the cause. A diuretic can do this as well but you haven't mentioned being on one. The antithyroid drug may be causing mild toxicity in your liver and your Dr. knows this but also knows that it will reverse and he won't allow any actual liver damage to take place.
