You will get better information from the cyst forum, this is the cancer forum.
Been there, done that. I would also suspect gas; excuse me for being blunt, but has she excreted alot of gas or had a movement? In any event, since it's four days after your post, I hope she is feeling better and I commend you, a man, a husband, for researching your wife's concerns! Not many out there like you and she is blessed! Best...... Elizabeth