The event monitor is WAY smaller than the Holter. About the size of a pedometer. You could probably stick it in your bra, but it probably would be uncomfortable. I needed to wear mine for only about a week, although it was approved for a month. You only need to wear it long enough to find something.
It's funny, there was nothing reported on my Holter recording either. But, once I had the SVT on the event monitor, the cardiologist said he reviewed my Holter again, and there were short episodes of SVT, but they were so short, they fell within the "normal" category, especially since they did not go long enough for me to note symptoms. You might also consider it when you take a vacation, or even a long weekend.
As to the carbs, I find that as time goes on, they are less and less important. I just rely on Imodium to reduce output. Even carbs with a low glycemic index need to be reduced, since they create an overall load to your pancreas. Sure, they are better than sugar and white rice, but you cannot have unlimited amounts. You may want to try Citrucel as a fiber supplement, since it has no psyllium. Less likely to cause gas.
Jan