Hi Diarrhea for a month- has to be looked into in detail. I would like to know the frequency of loose stools in a day, consistency of the stools, presence of blood in stools, presence of fever, diet he is on especially milk status. I would also like to know the results of stool examination if it had been done already. Stool routine examination, stool pH and stool for reducing substances. Cefuroxime axetil is an antibiotic and is given if the cause is likely to be bacterial. Bacterial diarrhea are usually associated with high grade fever, may have blood in stools, stool examination will show more pus cells. If so then antibiotic should be given for a minimum of 7 days. Viral diarrhea usually settle in 5 to 7 days. Since you say its there for a month, causes like Lactose Intolerance and Malabsorption etc should be looked into. So its better, if you can have stool routine examination, stool pH, stool for reducing substances and fat globules done so that management can be easy. Heart beating fast might be because he had fever at that time or dehydration. So please see how much fluid he drinks and what is the frequency of urination. If he drinks well and urine output is atleast 4 to 5 times in a day, then nothing much to worry. Now dietary management is very important since its a month of diarrhea now. Avoid cow s milk/ formula milk/ excess fruit juices. Breast milk can be continued. You may give soyamilk like ISOMIL. Diet should include fluids like water, coconut water, lemonade, ORS (Pedialyte), soups, dal water, curd etc. Include banana, rice based items, bread, boiled potatoes etc in the diet- these items act as stool binders and will help in reducing the frequency of loose stools. You may also give probiotics like Econorm/ Bifilac/ Enterogermina. Hope my answer helps. Please do get back with details if possible. Wish your son a speedy recovery.