Starting solid?

Ellie

The pediatrician told us today that we can introduce solids to our 4 month old. But a lactation consultant from the hospital said 6 months is recommended because that’s when their digestive tract would be mature. Should I wait or just introduce?

Edit: Not solids completely. I meant purées. So baby oatmeal with either water or breast milk. Or puréed veggies and fruits.