Hi, * Usually the head swelling should have been consulted for, immediately for some times, a mild hit too may cause of brain injury. You can put an ice pack to prevent excessive swelling. The baby is observed for 24 hours. Fortunately baby does not seem to have problem, except for pain & swelling. It can be taken care of by anti inflammatory syrup ( Paracetamol, Ibuprofen) * Biting, runny stools, irritation indicate teething.- - The irritation & fussiness is due to irruption pain. Analgesics & anti inflammatory drugs like Ibuprofen, acetoamenophen, paracetamol syrups help in certain extent. Vitamin & calcium supplements are helpful. - Application of glycerin borax Does have a psychological effect./soothing. - Runny stools are due to biting contaminated things/toys. A careful watch on baby & washing the play materials frequently prevents this. -Breast milk is best, boiled rice, water of boiled split pulses can be given Boiled water with ORS is needed to avoid dehydration. - For excessive diarrhea give antidiarrhoeals with a doctor s advice. -Teething powers ( biochemical) are helpful . Take care. Thank you.