The condition typically appears within the first three weeks of life
and almost invariably disappears, often very suddenly, before the baby
is three to four months old. It is more common in bottle-fed babies, but also occurs in breast-fed infants. The crying frequently occurs during a specific period of the day, often in the early evening.
Since the cause is not conclusively established (see below) and the
amount of crying differs between babies, there is no general consensus
on the definition of "colic". Having ruled out other causes of crying,
a common rule of thumb is to consider a baby "colicky" if he or she
cries intensely more than three days a week, for more than three hours,
for more than three weeks in a month.
Colic is uncontrollable crying in a baby that has no known cause.
The cause of colic isn't known. In the past it was thought to be
related to the digestive system. Painful wind may contribute to colic,
but there is little evidence to prove colic is linked to digestive
problems. Intolerance of lactose has also been identified as a possible
factor, but evidence is limited.
Another possible cause may be your baby's temperament. This may make
your baby highly sensitive to the environment, and he or she may react
to normal stimulation or changes by crying. If you smoke, this may also
be a factor.
All babies cry. It's a simple
and effective way of communicating: it's your baby's way of letting you
know they're hungry, tired, cold or need a nappy change.
Babies sometimes cry for no obvious reason even though they're
well-fed, clean, warm and well cared for. If your baby has repeated
episodes of excessive and inconsolable crying and they otherwise appear
to be thriving and healthy, they probably have colic.
Colic is very common in newborn babies and is thought to affect
around 20% of them. The condition normally starts a few weeks after
birth, and continues for the first three to four months of life.
Although it may appear that your baby is in distress, colic is not
harmful. Your baby will continue to feed and gain weight normally.
There's no evidence that colic has any long-term effects.
Colic can be very upsetting for parents. You may feel like you're
letting your baby down or that you're doing something wrong. However,
although colic can be distressing at the time, it is a common phase
which will pass in a few weeks or months.
NHS Direct
Colic is quite common, but no one knows exactly what it is. The medical
definition is crying in a healthy, normally developing baby, which
seems unrelated to pain or hunger, and which occurs most days or
evenings over a period of time.
Typically, colic starts in the first month, and goes on until your baby is three months or so.
It's
not known why some babies are affected more than others, or why it
sometimes suddenly disappears. It could be to do with immaturity of the
gut, and as the baby's digestion matures, they become more able to
tolerate the sensations of digestion. Alternatively, it may be bubbles
of trapped wind, causing discomfort.
BBC Parenting