Firstly Thank you for giving proper description. According to your description iron supplement causes discolouration. My advice is consult pediatrician to know if it will go back to normal. Use dropper to make sure that teeth does'nt come in contact with iron supplement. another reason can be early childhood caries, nursing bottle caries etc. Give water to child after feeding and iron supplement. Clean the teeth and oral cavity with soft cloth after feeding. Also it is normal for a baby's gums to bleed a bit while teething. A baby may also have some tenderness, swelling, bruising, and pain associated with erupting teeth. When a baby is teething, bleeding gums are usually caused by teeth breaking through the delicate tissue in the gums.

Yes iron supplement causes teeth discoloration. Make sure the syrup doesn't come in contact with teeth. Use dropper. Consult pediatrician to know more methods for consuming iron without damaging teeth. These may also be early childhood caries (tooth decay), rampant caries, nursing bottle caries. Clean teeth and oral cavity well after every feeding. Give to water to the child. Clean mouth even after night, midnight feedings. Avoid bottle feeding. Kindly go through the blog mentioned in the link below.