Hello my friend I am Dr.Arianisa Thanks for your question on HCM The most common cause of diarrhea is infection--viral, bacterial, and parasitic. 1.Viral gastroenteritis (viral infection of the stomach and the small intestine) is the most common cause of acute diarrhea worldwide 2.Disease-causing bacteria usually invade the small intestines and colon and cause enterocolitis. Bacterial enterocolitis is characterized by signs of inflammation (blood or pus in the stool, fever) and abdominal pain and diarrhea 3.Parasitic infections are not common causes of diarrhea. Infection with Giardia lamblia occurs among individuals who hike in the mountains or travel abroad and is transmitted by contaminated drinking water,or at kids eating without washing their hands . Many home remedies have been suggested for the treatment of diarrhea; however, few of them have been well-studied like:pectin,cooked green bananas,probiotics, and drinking plenty of water. If your son is not getting better than you should meet your GP ,so he can evaluate the situation as making physical examination,fecal culture too Hope this information is helpful to you Best regards