Bowel cancer if bloods clear?

 Hi there

My husband has been having serious stomach issues for 2 months now. He's intermittently been passing blood but passing mucus several times a day with stomach cramps. He has been getting tests and is awaiting a colonoscopy. We have bowel cancer in the family so are obviously concerned. He's been told he has a positive QFit and a very high inflammation level of 498 from his stool sample. However on a positive note his bloods are clear. I just wanted to ask if it was bowel cancer I assume the bloods would indicate this?  

Thanks in advance

From a worried wife