Fried rice isn't a safe choice since it's fried, and greasy/fatty/fried foods often mess up people with IBS. A better bet next time is steamed white rice and to avoid any fried foods, like General Tso's Chicken. Most Chinese food, though, is pretty low in fat, although a lot of the sauces they use on buffett foods are full of sugar.
You need to have your gall bladder checked by ultrasound and hida scan as getting up in the middle of the night is very much associated with a bad gall bladder (although some IBSers do sometimes get up with D in the night). Also the feeling of being overly fully after a small amount of food, of choking, of having food sitting in your esophagus, etc. are all signs of a bad gall bladder. As is a high intolerance to fatty/greasy/fried foods. Other signs of a bad gall bladder are yellow or green colored stools, stools that burn when they come out and leave your rectum burning even when you're done, vomiting, pain high in the abdomen and often (but not always!!!) along the right side, pain up into the chest and back, especially up into the right arm, shoulder blade and even down into the elbow, and an inability to lie flat on your back when you're sick (it makes you sicker to lie down).
Unfortunately IBS, gas and GERD can all mimic these symptoms, but the more of them you have, the more likely you have a bad gall bladder.
My fiance quit smoking almost four years ago and he still coughs more than a normal person ought to. He's also bad about coughing up stuff if he gets the tiniest bit of a cold or allergies. In fact, I think he may have coughed up stuff regularly for a year or more after he quit, but now he only coughs up stuff when something sets him off--but he still just coughs quite a bit, especially in the mornings. I saw a paper once that he had printed out that listed how many YEARS it takes your lungs to repair themselves after you've been smoking for a certain length of time. I think after 5 or 10 years of smoking it takes like 20 years of not smoking for your lungs to go back to looking like normal. So the damage can be repaired, but it takes a really, really long time. Of course, your coughing up stuff may be related to some sort of allergic reaction to food, h. pylori or some other gut problem, but I think you're probably right in guessing that it's smoking related. I bet the American Lung Association would have more information on how long it takes your lungs to repair themselves and what you can expect to happen while that's happening.