This paper explores two areas in which the translation of research into practice may be improved in the management of cry-fuss behaviours in the first few months of life. Firstly, babies who cry excessively are often prescribed proton pump inhibitors, despite evidence that gastro-oesophageal reflux disease is very rarely a cause. The inaccuracy of commonly used explanatory mechanisms, the side-effects of acid-suppressive medications, and the failure to identify treatable problems, including feeding difficulty when the diagnosis of ‘reflux’ is applied, are discussed. Secondly, crying breastfed babies are still prescribed lactase or lactose-free formula, despite evidence that the problem of functional lactose overload is one of breastfeeding management. The mechanisms and management of functional lactose overload are discussed. These two problems of research translation need to be addressed because failure to identify and manage other causes of cry-fuss problems, including feeding difficulty, may have adverse outcomes for a small but significant minority of families.