My Mum Had An Emergency Op For A Strangulated Hernia

My mum had an emergency op for a strangulated hernia and a few days later before she came out of hospital she was rushed back into theatre with a perforated bowel, she was 81, she's now 85. She now has another small hernia under her belly button. This has been checked by her surgeon only a few weeks ago but tonight she has called me to say she can feel a lot of liquid above her belly button, is this something to worry about? She doesn't have any pain or redness. 5thankyou
Sue