Why do people with bowel cancer in the first stages bleed diarea, and have mucus in thier poo?

And why do they feel anemic and tired sometimes but not all the time? Any advice as to why. Please help. Thank youWhy do people with bowel cancer in the first stages bleed diarea, and have mucus in thier poo?
Because they are sick, but in a different way to you!
It is extremely common to notice a few spots of blood on the toilet paper after passing stools. If there is no blood in the toilet bowl, this is most likely to be due to minor damage to a blood vessel in the skin of the anus. If it persists, the problem requires investigation to exclude significant disease of the anus.

Blood in the toilet bowl that is separate from the faeces and is bright red is commonly due to bleeding from haemorrhoids (piles). However, this sort of bleeding cannot be distinguished from bleeding due to a rectal cancer without further investigation.

Blood that is mixed in with the stool is more likely to have a worrying cause but benign (non-cancerous) possiwbilities include bleeding from diverticular disease or from colitis.
****thats all i know