8 yr old child has had intermittent abdominal pain, and heavy mucus in stool for approx 2 weeks. 3 wks ago, child finished med for ear infection. has allergies, tendency to snuff. also had severe constipation when very young, appears to stretched colon, as when he passes, it is unusually large. Should i be concerned about ibs, or possible blockage, or might it be just mucus running through his system