Sigmoidoscopy instead of colonoscopy?

Hi,

I'm 27 F, had rectal bleeding on and off for years which I ignored (I know that's stupid), finally went to the doctor and had a positive FIT test.

I've been referred for a sigmoidoscopy but where ever I look online it says you should get a colonoscopy after a positive FIT. I've asked my Gp about this and they said because of my age and length of symptoms its probably hemorrhoids and the sig is less invasive. Is this similar to other people's experiences?

Lately I've noticed my bowel movements have been more loose amd frequent but that could be due to how anxious I've made myself feel thinking I've got bowel cancer.

Thanks x