Dear Ceebs,
Sorry to here you are having this trouble with your little one it must be quite distressing for you.
There are several factors that may be involved in causing your infant's colic -
1. food allergy or intolerance to cow's milk
2.Intolerance to lactose
3. Intestinal hyper-peristalsis ( when the intestines contract too much to push the food along)
4.Imbalance of serotonin and melatonin. Too much srotonin cause again too much intestinal contractions and hence the reflux

The reason you are finding your infant is less inclined to eat is because the way losec works is to slow down the intestinal contractions to reduce the pain and reflux. This also results in the digestive system becoming less active and able to work properly and thus not really wanting to feed.
Natural therapies approach it differently
The first thing is to find out if your infant has any food sensitivities.
Another important thing is to make sure that the baby has the proper balance of flora in their gut ( often if delivered by caesarian section) they don't pick up the mother's flora as they come down the birth canal or if have you had any antibiotics during pregnancy they may be out of balance too.
As your infant is over 3 months the serotonin and melatonin should be balancing themselves out now so the food sensitivities is probably the most likely cause
If you are near the Belly Belly Pregnancy centre in Melbourne do make an appointment and we can see if we can sort this out for you and your little one.
Best wishes
Jocelyn King