Help please desperate?

my baby is 5 months old and formula fed and she has very irregular bowel movements and the doctor insisted that i start her on solids because she is in the lower end of the percentile for weight. so i started her on solids and she hasnt gone poop since now tonight she is screaming bloody murder and only sleeping when she is too exausted to cry anymore. she hasnt pooped since the day before yesterday... so i gave her a tiny little piece of a glycerin suppository i have done this before and it always makes her go right away when she really needs to. but tonight nothing she hasnt even tried to push after the suppository only scream she has never screamed like this before like she is in pain. what should i do should i go to the hospital?