sudden weight gain!!!!!

I'm back, i had my surgery about 5 years ago, i lost over 100lbs! Now, after having had gallbladder surgery, i have gain 10 lbs in 2 weeks. I am scared to death! As we all know, the thought of gaining any weight back is a scary thing for us all. Is there any suggestions as to how i can lose these 10lbs, sudden and unwanted lbs? I'm freaking out here! Help!