Brief Answer:
Some of the most common causes listed

Detailed Answer:
Hello ma'am and welcome.

Thank you for writing to us.

I have gone through your query with diligence and would like you to know that I am here to help. Diarrhoea lasting for about 4 weeks, especially without a fever (which you would have mentioned, if it were to be present), is usually related to abnormalities of the digestive system. Let me list some of the most common causes for your reference, but I will also recommend scheduling an appointment with a gastroenterologist:

+Diverticulosis
+Irritable bowel syndrome
+Crohn's Disease
+Inflammatory bowel disease
+Ulcerative colitis
+Intestinal polyps
and a few other conditions.

And so I would strongly recommend the gastroenterology consultation along with investigations like an upper GI endoscopy, a colonoscopy, complete hemogram, etc.

I hope this helps. But please do not hesitate to write back to me for any further clarifications, I am always here to help.

Best wishes.

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