"Ovarian cancer is a rare but deadly reason for a bloated belly. It usually goes along with other <a href=""http://www.bmj.com/content/339/bmj.b2998"" target=""_blank"">telltale signs </a>such as abdominal pain, urinary frequency, postmenopausal and anal bleeding, and a loss of appetite. So if you've suddenly developed abdominal distension in the past few months and have any of these other symptoms, see a doctor immediately. And don't rely on the results of your Pap test; that's effective only in the early detection of cervical cancer."