Good evening, the child has had dark green stool for four days. Before…

Good evening, the child has had dark green stool for four days. Before that, there were constipation, they took Duflapak for 7 days. After finishing the treatment and appeared dark green stool. The child eats as before, weight is gaining, sometimes pulls legs towards the belly and cries. What could it be? Dysbacteriosis or side effect after Duflapak?