Girls, share your experience, who on I.V. I can't understand if the mi…

Girls, share your experience, who on I.V. I can't understand if the mixture doesn't suit us or it's just colic time. I don't remember with the older one being so troubled like this. After feeding, he poops with such force, gas immediately accumulates, cries, reddens, twitches. He asks to eat every 2 hours, as if he's not eating enough, but the doctor allowed it because he's small and needs to gain well. He seems to be gaining well, but these gases and stool. Either the gut is so insistent or try another mixture? On Nutrilon in a new packaging there are so many bad reviews specifically about the gut reaction, everything like