Since your baby has been passing stools quite frequently and without difficulty, it rules out constipation
as a cause of bleed. There are however other causes of blood in stools. Common causes are allergic colitis
and anal fissure
is rare in a one month old.
Please ensure that the formula is prepared as per the instruction manual. Since there is mucous along with blood, get a stool test
done to rule out stool infection. It is not uncommon to acquire infections in formula fed babies . Ensure proper handwashing when preparing feeds for your baby.So get your baby examined with a neonatologist once to be absolutely sure.