Baby colic, also known as infantile colic, is defined as episodes of crying for more than three hours a day, for more than three days a week, for three weeks in an otherwise healthy child. Often crying occurs in the evening. It typically does not result in long-term problems. The crying can result in frustration of the parents, depression following delivery, excess visits to the doctor, and child abuse.The cause of colic is unknown. Some believe it is due to gastrointestinal discomfort like intestinal cramping. Diagnosis requires ruling out other possible causes. Concerning findings include a fever, poor activity, or a swollen abdomen. Fewer than 5% of infants with excess crying have an underlying organic disease.Treatment is generally conservative, with little to no role for either medications or alternative therapies. Extra support for the parents may be useful. Tentative evidence supports certain probiotics for the baby and a low-allergen diet by the mother in those who are breastfed. Hydrolyzed formula may be useful in those who are bottlefed.Colic affects 10–40% of babies. Equally common in bottle and breast-fed infants, it begins during the second week of life, peaks at 6 weeks, and resolves between 12 and 16 weeks. It rarely lasts up to one year of age. It occurs at the same rate in boys and in girls. The first detailed medical description of the problem was published in 1954.
Babies who cry may simply be hungry, uncomfortable, or ill. Less than 10% of babies who would meet the definition of colic based on the amount they cry have an identifiable underlying disease.Cause for concern include: an elevated temperature, a history of breathing problems or a child who is not appropriately gaining weight.Indications that further investigations may be needed include:
Vomiting (vomit that is green or yellow, bloody or occurring more than five times a day)
Change in stool (constipation or diarrhea, especially with blood or mucous)
Abnormal temperature (a rectal temperature less than 97.0 °F (36.1 °C) or over 100.4 °F (38.0 °C)
Irritability (crying all day with few calm periods in between)
Lethargy (excess sleepiness, lack of smiles or interested gaze, weak sucking lasting over six hours)
Poor weight gain (gaining less than  15 grams a day)Problems to consider when the above are present include:
Infections (e.g. ear infection, urine infection, meningitis, appendicitis)
Intestinal pain (e.g. food allergy, acid reflux, constipation, intestinal blockage)
Trouble breathing (e.g. from a cold, excessive dust, congenital nasal blockage, oversized tongue)
Increased brain pressure (e.g. hematoma, hydrocephalus)
Skin pain  (e.g. a loose diaper pin, irritated rash, a hair wrapped around a toe)
Mouth pain (e.g. yeast infection)
Kidney pain  (e.g. blockage of the urinary system)
Eye pain (e.g. scratched cornea, glaucoma)
Overdose  (e.g. excessive Vitamin D, excessive sodium)
Others (e.g. migraine headache, heart failure, hyperthyroidism)Persistently fussy babies with poor weight gain, vomiting more than five times a day, or other significant feeding problems should be evaluated for other illnesses (e.g. urinary infection, intestinal obstruction, acid reflux).