Ideally you should wait till completion of 6 months to start solids.
Once you start solids there is change in the consistency of motions (either loose or hard)
Do not skip breastfeeding/formula feeding and keep offering it on demand.
Also ensure your water intake is also good (atleast 3 L a day), if breast feeding.
Next Steps
Stop solids till completion of 6 months of age.
Monitor baby’s urine count till motions settle.