Swollen abdomen mostly on left side

Hi. My mother, a 72 year old woman had hysteractomy 14 years ago. Two years ago, she was diagnosed by severe Osteoarthritis and Disk Degenerative Desease of lumbar. Since 10 months ago, her left abdomen start swelling and very sensitive to any touch. CT scan from abdomen was negative and Colonoscopy findings were negative also. Day by day her abdomen is getting larger and larger. Is any knowlegable doctor out there to help me with this issue?