Hi. Is  your child on formula feeds? If so its quite normal to have green stools on formula feeds. If on breastfeeding did your diet include lots of greens lately? Wait for couole of days if not associated with any other symptoms.

Food may be moving through the large intestine too quickly, such as due to diarrhea. As a result, bile doesn't have time to break down completely. Green leafy vegetables, green food coloring, such as in flavored drink mixes or ice pops, iron supplements. A lack of bile in stool.

As long as there's no blood in stools OR it's tarry black,relax!! At this age,you need to give 3 solid meals a day including curd and Banana in the diet in addition to whatever you prepare at home and 3 milk feeds including one top milk feed using a spoon and katori and rest breastfeedings. If stools are soft and formed,do nothing. If loose,add Enterogermina vial half vial twice a day for 3-5 days.