Bright yellow runny diarreha

My mother has the same and has been diagnosed with diverticulitis and has a cyst on her pancreas. It is being drained at the moment. She has had runny yellow stools which are very greasy (as i realized when cleaning the toilet). she also has pains on her left and right side. she always feels cold too. She has been like this for over a year and she has also seen a dramatic weight loss from 7 and a half stone to 5 stone 7.