I've been having diria for almost 4 weeks and going to the toilet a lot. So can you please tell me the natural cure for it?

in that case you really should see adoctor. it is not normal to suffer from diarrhoea for that long so you should get checked out just in case its a symptom of something serious. also prolonged bouts of diarrhoea can lead to other complications such as dhydration and malnourishment.
some natural cures are eating bananas, also drinking black tea is supposed to help clear it up. make sure you drink plenty of fluids and ideally take some rehydration salts, like 'dioralyte'.