Of course I'm not a doctor, but seeing the word "tight" makes me think gallbladder right away!! Just had mine out in Dec. and I LCed my way through the whole thing. I had a bad one before I started LC. I believe it was from so much very low fat eating I di for several years. This caused my gall bladder to sit idle and gather guck, make stones, etc.
Not sure of course and it could be gas, but could be a gall bladder pain. Don't worry if it is... it's fixable and not needed anyway. I feel great now.
Good luck!
Cheers,