My baby is nearly 4 months old and for the past few days I've noticed that she is straining a lot then sometimes crying after. She poos once a week which doctors have said is normal but have prescribed lactulose for the straining as they think she is constipated. However, after reading up what lactulose is, it seems more of a stool softener and when my baby does eventually have a poo it is always soft and runny. Does anyone have any advice, should I be changing my diet as I'm exclusively breastfeeding? My baby spits up a lot and always has done, putting on weight as normal. Has anyone been in the same situation? I'm just getting worried and my doctor doesn't seem to be helping.