Sorry if I’m thick but I just want some insights/clarification on this as I'm studying for MSRA and the guidelines are confusing me a bit😭

In GP settings, if a 60 year old patient who has long standing constipation and a week ago, has had diarrhea and bloody stool and low grade fever. If we suspect diverticulitis, would we still do FIT test and refer them to 2week referal for colonoscopy as this person’s bowel habits have changed? And is there any point doing FIT test if this person will have blood in their stool anyways?

I'm discussing this guideline https://cks.nice.org.uk/topics/gastrointestinal-tract-lower-cancers-recognition-referral/

Sometimes these guidelines would say to refer if symptoms cannot be explained by other diagnoses (for example: under 50s years with unexplained rectal bleeding), but on the symptom of “With a change in bowel habit” it didn't say it has to be unexplained.

That is also the same thing for the statement "Aged 60 years and over with anaemia even in the absence of iron deficiency.”.

What if we suspected it’s due to non-cancerous causes of anaemia, do we still refer to 2ww if it’s explained?

Thank you🥹