Hello, Welcome to HCM. Diarrhea is a very known side effect of co-amoxycalv. Amoxycilline disturbs the normal gut bacteria which leads to diarrhea. As you have already finished the course of antibiotics, I hope it will settle soon. Take care of your hydration and have plenty of liquid like water, fresh juice, thin soup and lime water but avoid cola drinks. You should also take plenty of butter milk & curd if you are not allergic to it. Here, taking probiotics can help you a lot. You should start any probiotic preparation containing Lactobacillus rhamnosus or Saccharomyces boulardi available over the counter. Most antibiotic associated diarrhea are self limiting and subside by its own but if the severity is increased, you have blood/pus in stools, have high fever or severe abdominal pain than you should consult your doctor. Hope this will be helpful. Do ask if any more question is there. Take care.