starting my 5 month old on solids

Kayley • 24 years old, I have a little boy who’s 4 and I’m TTC my second baby!! 👶🏻
The reason for me started solids at 5 months is because my son has colic, and health visitor and doctor said the colic would clear if I put him on solids. I was going to start him with some porridge, can I buy normal porridge oats or does it have to be baby porridge because he's only 5 months?