If there is past family history of 2 deaths from bowel perforation (1 colonoscopy, 1 cdif) could there be increased risk for other family members?

No: Is is very rare for bowel perforation with colonoscopy or even deaths with the procedure. The procecure is usually. Short and safe , the same for clostridium difficile infection( i assume you mean that in short) that cause perforation and deaths.It is not genetic.

Not clear: If i understand what you are asking, there is no risk to have bowel perforation because others had it. Specially from a colonoscopy. Cdiff is an infection and the only risk is to get the infection from the relative that had it.