A BMJ paper published in 2007 reviewing treatment of colic examined the evidence :
"One poor-quality randomised controlled trial (RCT) found limited evidence that simethicone reduced the number of crying attacks on days 4?7 of treatment compared with placebo."
By poor quality the BMJ clarify that there were only 26 infants aged 1-12 weeks in the study and no reported details on how cases of colic were defined.
Oh that's disappointing. But surely GP's and all these other health professionals aren't suggesting or prescribing infacol on the basis of a "poor quality" small study of 26 babies? A study that doesn't define nor claim to ease colic, but refers to "crying attacks" which could potentially have any cause or be of any frequency?
The BMJ discuss two other trials that do define colic, perhaps these are more compelling.
First is a double-blind, crossover of 83 infants aged 2?8 weeks, comparing 0.3 mL of simethicone versus placebo for a week before feeds.
"It found no significant difference in colic (using the standard colic definition), when rated by carers, between simethicone and placebo (28% improved with simethicone v 37% with placebo v 20% with simethicone plus placebo.)"
So a study three times the size of the first, found Infacol was actually 9% LESS effective than a placebo at helping colic?
Let's try again.
The second study (double-blind, crossover trial, 27 infants aged 2?8 weeks) found no significant difference between simethicone and placebo (10 drops before meals, duration of treatment 24 hours) in improvement as rated by parental interview, 24-hour diary, or behavioural observation.
In fact the BMJ conclude:
"Further trials are not considered to be of clinical importance and are unlikely to be undertaken. According to the available evidence, there is no reason to use simethicone in the treatment of infantile colic."
Yet the NHS website states:
"This medicine helps relieve griping pains and colic in babies and infants which may be caused by swallowing air."
Does it NHS? Says who? Infacol themselves with their "clinically proven" claims? The BMJ disagrees!
What about reasons not to?
Let's look at the other ingredients in Infacol besides Simethicone.
Purified Water
Hypromellose
Orange Flavour
Saccharin Sodium
Methyl Hydroxybenzoate (E218)
Propyl Hydroxybenzoate (E216)
Obviously these ingredients have been approved for use in this product, but when weighing up whether to use or take a medicine, we typically consider the benefits that can be obtained, versus any risks or downsides.
The literature surrounding infacol states that Simethicone is not absorbed into the body and thus is unlikely to cause harm (although some parents do report perceived side effects and some more here), but some do warn that Methyl and propyl hydroxybenzoates (E218, E216) may cause allergic reactions (possibly delayed)
Furthermore E216 and E218 are parabens considered controversial by some and even taking this out of the equation, has anyone considered the potential the impact to the baby's gut flora of putting a product containing fungicide, combined combined with artificial sweetener and a dollop of orange flavour in his digestive system several times per day for weeks at a time?
All for something that evidence suggests doesn't work?
What's also interesting is that there is a mounting body of evidence that probiotics may be an effective tool in reducing infant crying, including a trial that directly compared them to Simethicone:
"Eighty-three infants completed the trial: 41 in the probiotic group and 42 in the simethicone group. The infants were similar regarding gestational age, birth weight, gender, and crying time at baseline.
On day 28, 39 patients (95%) were responders in the probiotic group and 3 patients (7%) were responders in the simethicone group.
And it's not an isolated study,two more studies highlight effectiveness of probiotics for colic.
So why then aren't GP's, health visitors and midwives prescribing and recommending them instead of something seemingly no more effective than a placebo?
Taken from a blogger who imho raises good points. I am not expecting you all to agree but we can agree to disagree without the 
Bobyan I have no idea what medicine the OP has been prescribed.
She hasn't said nor has she confirmed what her baby has. Not my business. I used the word placebo badly as I did not mean placebo effect on baby rather than the effect on parents. Do I feel relieved/better if I give my child Calpol for a fever? Short answer yes - it feels like I am doing something - even though there is a train of thought that we should let fevers run as the body's natural defence mechanism.
Ditto for cough medecine use.
I am not saying colic is imagined thank you very much - as stated my DC1 had it - I am saying that there are alternatives to simethicone.
I do not think GPs hand out medication like sweets - far from it particularly when it obviously won't help eg antibiotics for a virus.
I am saying however that sometimes medicine is prescribed that is ineffective eg simethicone based medicine.
There are also alternatives to standard prescriptions eg breast milk will naturally sort sticky eye rather than fucithalmic acid.