My daughter had colic starting at 6 weeks. She was the same way with the grunting and the whimpers. The gas drops seemed to only make it worse for her. Here is a suggestion that worked WONDERS for us:
first of all lay her on her back and bring her knees into her chest - repeating this over and over...you may need to raise her legs up a bit when doing this. It helps to release some of the gas pressure...
Secondly I do what is called a super swaddle...
you lay a blanket flat out....fold the TOP corner down and lay baby so head is above the folded corner. Next you are going to take the right side of the blanket and tightly wrap over top of right arm and UNDER baby, do the same with the left side. Make it snug though. Next take the bottom portion and twist up and tuck sides in to both right and left. Next you will do a backwards regular swaddle that I am sure you learned in the hospital.
After you have the babe in a superswaddle give her a nonny (pacifier- I wasn't going to use one at all and the pedi recommended it for the colic) and sway and bounce with baby in a football hold in your arm.
This worked wonders with us and we did this for months. It is really tough seeing them like this and your pedi is right it WILL pass. Some babies it just takes longer.
A. & Emily Grace (5 months)