Doesn't sound like white spot (ich) from your description. Ich looks like the fish has been sprinkled with salt. A swollen stomach can indicate a number of things.
I would first of all stop feeding the fish if it's still eating. Test the water to make sure it reads 0 ammonia, 0 nitrite and low, (less than 20ppm) nitrate.
Is the fish having difficultly swimming? Is it sitting on the bottom or 'stuck' at the top?
You haven't provided much in the way of information so I can't really advise you further. If you want to post back please answer the above questions and also let me know how long the fish has had these symptoms, how long you've had the fish and whether the fish is still eating. Also please describe the white growths: fuzzy? Slimmy? Scales missing? Growing noticeably?