For some reason spring and fall seem to be popular times of year for horses to colic. We don't know if it is change in pressure, warm days with cooler nights, horses drink less, there are many possible theories. Regardless of the reason, us horse vets are always busier in these seasons. Luckily most colics we see are mild and respond to basic medical treatment, but it is good to pay attention to any change in your horse's behavior. If your horse seems less interested in feed, is not passing a normal amount of manure, is lying down more than normal, pawing, or lying down and repeatedly rolling, these are all signs of colic. If you see these signs take any food away, try to do a brief exam and possibly get a heart rate and temperature, and then contact your vet.
I wish I could say there is a magical preventative treatment for colic, but then I would be rich. The best thing is to make sure your horse has fresh water available, good feed, up to date on routine vaccines/teeth/deworming etc, and know any idiosyncrasies your horse may have.