My son has diarrhea but has no fever. Not sure what it is, and suggestions?

Help define problem. First define the problem (does he have soft or frequent stool?), circumstances under which diarrhea developed (malabsorption, pancreatic maldigestion, food intolerances, stressful times, exposure to ill individuals, food poisoning, ischemic gut, inflammatory colitis, etc.), severity (stool volume, dehydration, blood, night-time awakening, weight loss), & duration. The "cure" depends on diagnosis.