Table 1.

Proposed characteristics of colic, IISMO and IFCIDS syndromes of infancy

Characteristics	Infant Colic	Irritable Infant Syndrome of Musculoskeletal origin	Inefficient Feeding Crying Infant with Disordered Sleep
Common age range	2 weeks–3 months; Onset most commonly within first 2 weeks	3 weeks to 3 months but may occur outside of these ranges, infant needs ability to hold antalgic posture	1–6 months (seen less frequently 7–12 months)
Crying patterns	Loud, disturbing, relentless unsoothable crying often late afternoon/evening	Crying may be high-pitched at any time of day. Often triggered by positioning child out of position of comfort	Many episodes and long bouts of crying, peaking during the day; high intensity, priercing cries common
Physical presentation/behaviour	Tense abdomen, flexed posture, kicking, flailing legs and boxing arms. Unconsolable whether picked up or not.	Antalgic posture held for sake of comfort; asymetric movemetns/unilateral spinal hypertonicity; tactile defensive; musculoskeletal sensitivity.	“Pained faces” (facial grimaces) accompany crying; body unrest, arching postures, general irritability and difficult to soothe; difficult to distinguish from colic crying/movements, but not limited to end of day and longer hours
Other signs/symptoms	Appears in pain, changes from happy to crying in an instant, wants frequent cuddling but may not respond	Restless sleep; may not wish to rest supine (some will only sleep in car seat); affective disorder common.	Male predominance (60:40); feeding problems common, sleep disorders common (difficulty falling asleep and staying asleep)

After Miller, 2007