TABLE 1.

Current explanatory models for cry-fuss problems.

Theoretical model	Key management strategies	Summary of evidence
Medical condition		Not supported by evidence (Douglas, 2013;
(1) ‘Reflux’ or GORD	(1) Anti-secretory medications	Bergmann et al., 2014; Gieruszczak-Bialek et al., 2015;
(2) Allergy	(2) Maternal elimination diet	O’Shea et al., 2017; Gordon et al., 2018)
(3) Tongue-tie or upper lip-tie (in absence of classic tongue-tie)	(3) Frenotomy
(4) Lactose intolerance	(4) Lactose-free formula
Normal developmental phase (Zeifman and St James-Roberts, 2017)	Support carer coping. Reassure crying will pass Entrain infant biology with first wave behavioral (FWB) strategies.	Ignores evidence that crying durations are modifiable by infant care practices (Wolke et al., 2017). High level evidence shows that FWB strategies do not decrease night waking (Bryanton et al., 2013; Douglas and Hill, 2013b; Kempler et al., 2016; NHMRC, 2017)
‘A mysterious disorder of the microbiota-gut-brain axis’ (Partty and Kalliomaki, 2017; Rhoads et al., 2018; Zeevenhooven et al., 2018)	Probiotics	Probiotics may decrease crying in breastfed infants (placebo response 66%) but studies do not control for the breastfeeding problem of functional lactose overload and do not take into account complex bidirectional nature of gut-brain axis (multiple confounders). Gut dysbiosis is a confounder, not a cause (Fatheree et al., 2017; Sung et al., 2017).
Neurobiological (Douglas and Hill, 2013a)	Neuroprotective Developmental Care, which Integrates lactation and sleep science, neuroscience, brain- gut-microbiota science, evolutionary biology, applied functional contextualism.	Preliminary studies positive (Douglas et al., 2013; Ball et al., 2018) Requires further research.