Sweetcorn is a good source of folate. It also helps protect against age-related macular degeneration and helps fight free radicals in the retina. It provides more starch and more calories than most vegetables. It is high in iron and potassium. It is also a good food for steadying blood sugar.
Sweetcorn is fairly high in calories so don't overdose.
I think the parts that aren't digested ar just the shells of the kernels..the inside part is very good for you, as Octavius has quite rightly pointed out :o)