What Causes Swelling In Groin Area?

my husband has a very swollen groin area also the little fat stomach thats over his groin is swollen . his big stomach is ok . he went to the nanicke hosp. 2/22/15 for 5 days gave him some iv s and sent him home . Took him by amb to ER and they nsaid there was nothing they coud do. I thought maybe they could maybe drain it or something . Of course I am not doct. Thank you for any help that you can give me. mrs Smith.