1-month-old baby can't have a bowel movement?

To talk about constipation in a 1-month-old, first make sure they really can't have bowel movements. At this age, breastfed babies sometimes go 3-5 days, or even longer, without pooping — this is often not constipation but rather the result of breastmilk being almost completely digested with minimal waste. What matters is the baby's overall condition: are they content, is their belly soft, can they pass gas, and is their appetite normal? If all these are fine and the stool that eventually comes is soft/liquid in consistency, this is physiological and doesn't require intervention.

However, if the baby is truly straining, their belly is hard, they're fussy, refusing the breast, and the stool that comes is small hard lumps, then constipation should be considered. In 1-month-olds, the most common cause is incorrect formula preparation (using too little water, not too much). Additionally, rarely, a congenital condition like Hirschsprung disease could occur. Safe home interventions are limited: making bicycle motions with the legs, gentle clockwise belly massage. Never give babies water, fruit juice, olive oil, molasses, suppositories, or enemas.

Time to consult pediatrician: if the baby hasn't pooped for more than 48 hours and shows the discomfort signs above, or if blood comes with poop, or if the belly feels tense and the baby cries when touched.