Borderline stool sample test, bowel cancer?

So my mum is 53 and she's had continuous bowel/stomach issues over the past few years basically going toilet a lot and recently a pain in her stomach so she had a ultra sound and a mri or ct scan and nothing came up. She did a stool sample and it came back borderline and they give her a number to ring and they mentioned something about bowel cancer is what they will be checking for (I wasn't there at the time of the call). She's obviously absolutely terrified and so am I and my grandad just having lost my nan 2 years prior to ovarian cancer. The thing I'm just so confused about is my mums has multiple stool samples in the past few years. She's had at least 2-3 this year alone and nothing had come back with anything. Just in October of last year she had five polyps removed and all of them were benign. The report said: "they include polyps called tubular adenomas with ad most low grade dysplasia. 
 

So to get this news it's confusing and very scary. Unfortunately I didn't find out until Friday 4pm and all the numbers we were given are closed until Monday and it's really hard as I can't call anyone for clarification so I thought I would post this here for some support. Many thanks guys