I don't understand why you DIDN'T ASK HIS PHYSICIAN. Plus, hospitals all have staff dieticians who's job it is to offer advice on post-surgical diet.
I'll give some general advice, but you should check with a medical/clinical nutrition professional for the details. Under normal conditions, the liver produces bile, and delivers it to the gallbladder, where it is stored until it is needed. After a meal, especially one high in fat, the gallbladder is stimulated to squirt its stored bile into the gut, to aid in the digestion/absorption of the fat. Since your husband no longer has a gallbladder, he is no longer able to deliver a huge bunch of bile quickly--instead, it now trickles into the gut as it is produced. The bottom line is, that he can still eat well, he just can't eat 1) large meals, and 2) meals containing a lot of fat. He should eat smaller, more frequent meals, and especially cut out high fat items. He can still have ice cream, he just can't eat half the damn carton at one sitting anymore. He can still have eggs, but cut back on the yellow part. Toast without all the butter. He really shouldn't be eating junk food anyway, but this will be a good incentive to cut that crap out altogether--since it's typically loaded with fat.
He basically needs to go easy on his digestive system from now on. No more Big Gulps, no more Big Macs, no more of the typical obesity-inducing, American crapola diet. Otherwise, he's going to constantly suffer from pain, gas, steatorrhea (fatty diarhea), and generally feeling like doo doo. He'll get used to it, and so will you. NOW GO TALK TO HIS DOC.