The odds of having bowel cancer at the age of 38 with a clear sigmoidscopy and a negative FIT test are so low, I suspect they are close to nil. I've read that the odds of bowel cancer with a negative FIT are something like 1%. And last summer at the age of 40, I had rectal bleeding, some weight loss, occasional loose stools (maybe once or twice a week) and trapped wind and the specialist said that at my age, bowel cancer was the least likely option and I would be the "unluckiest person in the world" if it turned out to be that. And I had not had a sigmoidoscopy and didn't have a FIT test.

Best of luck with the tests.