When it’s changing time, here are four diaper finds that clearly say it’s time to call the pediatrician.

1. Blood in baby’s stool. Might just be diaper rash, but it might signal a serious stomach condition, too. Call baby’s doctor.

2. Too much poop (diarrhea). It’s normal for newborn poop to be soft and frequent, especially when breastfeeding. But if they start getting very watery, overflow the diaper, or last more than six diaper changes, it’s worth a call to be certain.

3. No poop (constipation). Newborns should have at least one poop per day during their first month and usually one after every feeding. If not, they may not be eating enough. As they get older, babies can hold out on pooping for a few days (especially if they’re breastfed). If a formula-fed newborn baby doesn’t poop after one day, call the doc. Moms breastfeeding newborns should pick up the phone after two poop-less days.

4. White or black poop. Baby poop comes in a lot of colors, but bright red (blood) and chalky white or coffee ground black are causes for concern. Newborns’ first few full diapers will be dark and tarry, but any super-dark poops after the first week warrant a call.

If your baby is acting very fussy or not feeding well in these four situations, the best bet is to call the pediatrician.