Thank you for your query.
Kindly correct me if I have not understood the problems. They are:
1. Bad cough
2. Loose motions occasionally
3. Pointing to his buttocks that it hurts
I would suggest the following:
1. Give him some decongestant/cough syrup for his bad cough.
2. Get a stool routine examination for his loose motions.
3. Get his anal canal
examined by a doctor for any evidence of injury
I hope I have answered your query to your satisfaction.