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The green color of stools if it is loose motions and with pain in abdomen then it will be due to infection and if it is not painful and you just pass greenish or blackish stools once in a day then it can be if you are taking iron tablets to increase haemoglobin
;if it is so then it is normal.
If you have loose motions then you should get treated immediately because diarrhoea
can cause to land you up in pre-term labour which is not good for yur baby.Consult your doctor for immediate treatment.