Today my 4 years old boy went twice to the toilet. both times ob with blood in poo and green colour. he also complains about his bottom hurts!

Not uncommon: Bloody stools in children be due to a number causes. For example, they can be due to an anal fissure, food intolerance, infections, polyps, inflammation, etc. There are a few more serious conditions that also can exist, so a visit to the doctor is warranted in order to determine the cause.

See your doctor: Has your son had several days of diarrhea? Green colored poop can be normal after a child hasn't been eating normally for a few days and the blood could be from an anal fissue caused by the diarrhea. But blood in the stool could also be a sign of something more serious, so it's worth having your son seen by a physician.