Ita normal. when u initiate complementary feeding after 6months (food apart from milk) then there is transition in the digestion process because of which u will see changes in stool colour and frequency for few days till the baby body adapts.
No need to give ajwain water, whatever food u r preparing in puree forn, put little amount jeera and hing.
Next Steps
If u find child is uncomfortable or having pain during motion or has stopped accepting feeds or has become too fussy kindly get physical examination done