Hello! Please could somebody reassure me - my baby is almost 4 weeks old. She didn't regain her birthweight and stayed the same weight for 10 days so midwives and health visitor asked me to start formula top-ups of 2-3 oz after every other breastfeed, which we started on Monday last week. Since then she's only had one poo and passes wind often, usually with quite a horrible smell. Do I need to speak to a doctor or health visitor? Thanks very much!