Hi.. Welcome to HEALTHCARE MAGIC.. I have gone through your query and can understand your concerns.. As per your complain leaking ear with gooey discharge are indications of ear infection and as he has a recent history of cold, many a times cold leads to progression of infection in ear as throat and ears are connected via Eustachian tubes.. I would suggest you to consult an Paediatrician or an ENT expert and get evaluated and a thorough clinical evaluation and investigations like otoscopy, can help in diagnosis.. He can be advised antibiotic and analgesic ear drops for reducing infection.. In case if still the discharge does not stop, at times manual drainage of ears along with placement of pressure equalization tubes can help.. Hope this information helps.. Thanks and regards. Dr.Honey Nandwani Arora.