I'm worried as Fin hasn't pooed for a day or so and seems to be constantly straining and crying at the same time. He is like this most of the time. I am b/feeding apart from only 1 bottle of formula at night so can't understand it. I wouldn't have thought he was constipated. I hope somebody can help as I'm not sure what to do. Can I give him some cooled boiled water to try and help?