My 6 mth old had a small amount of mucus with dark brown hard bm. 27kcal formula , 2tsp of lactulose daily, just started solids, usually constipated?

See Pediatrician: Based on the information given, it sounds as though the child has other health/gi problems- 27 kcal is a very concentrated formula (breast milk and standard formulas are 20kcal/oz) and can contribute to constipation, which i assume is why you're already using lactulose. By itself, mucus in stool may or may not be worrisome, but any changes in premature or previously ill infants need assessment.

Constipation, premie: 27 cal. Formulas are premie formulas, given to premature babies in the neonatal intensive care units and sometmes for a few weeks after discharge. This baby should have been swithed to a regular formula, 20 calories, long ago. All babies on formula should be getting some water, because formulas are more concentrated than breast milk and frequently cause constipation.

High calorie formula: A 27 kcal formula is made for premature infants and has different calcium and phosphorus concentrations specific to the premature infant. Unless your child has failure to thrive from other medical problems would probably do better with a regular formula to give his kidneys and bowels a break.