DS2 is 5 weeks next Tuesday. Started on SMA Gold, but colic and constipation so switched to Aptamil Comfort, recommended by HV, it has helped with the above, but DS2 wakes up every 1hr 30mins at night for a feed. Is it not filling him up? He can only manage 90-100mls. Should I give him 'standard' formula as well. I am exhausted and want to improve things as DS1 starts primary school in September and I'm worried about coping in the mornings.