If you are experiencing diarrhea after taking prescribed vitamin C following surgery, it may be a side effect of the vitamin. It could be a good idea to stop taking it until you see your healthcare provider. If the diarrhea continues even after stopping the vitamin C, it's important to look for other possible causes and consult a doctor or pharmacist for further guidance. It's also essential to stay hydrated to prevent dehydration when experiencing diarrhea. Commercial electrolyte solutions can help with this. Remember to seek help if needed and take care!