Hi, Welcome to HCM. Green yellowish vomiting with green loose stools can occur in various conditions like excess unprocessed bile (which is to be digested by certain enzymes) or iron supplements,celiac disease or Protozoa infestation or following some intestinal infection etc Your child need to see physician and get your stool R/M examination with ultrasound get done. Continue to give him healthy foods with high vegetables which will improve our overall health if there is some relief from constipation related to paralytic ileus. Give h2 blockers (ranitidine) or proton pump inhibitors (pantoprazole or rabeprazole) will help to reduce excess acid production in stomach. Better to see his operating surgeon and get further evaluation by him to detect the exact underlying cause. Hope all your questions are answered. Regards,