Hi,
Welcome to HealthcareMagic Public Forum
Apart from intolerance to peanuts following are possibilities in his case:
-Food
poisoning, if symptoms are recent onset
-Gastrointestinal infection
-Development of tolerance to other food.
-
Irritable bowel syndrome.
Considering multiple possibilities as a cause, he need evaluation and testing by physician.
I hope this information has been both informative and helpful for you.
Wish you Good Health.
Regards,
Dr. Ashish Mittal
www.99doctor.com