Hi,
How long he is having this problem?
Constipation can make stool hard and dark coloured. In this case, treating constipation will take this back to normal.
For such cases, i used to give
bisacodyl suppository once to relieve rectum, and advise parents to give fibre rich items like oats,vegetable mix and fruit juice. Most babies will respond to this, otherwise needing a short course of laxatives. In later case, we should rule out
hypothyroidism too. Your doctor will guide in this.
If his stool is persistently grey even after relieving constipation, urine is yellow or if there is
jaundice, let us get his serum
bilirubin done to rule out obstruction to bile flow.
Hope I have answered your question. Let me know if I can assist you further.
Regards,
Dr. Muhammed Aslam T. K., Pediatrician