There are multiple different causes of diarrhea. Diarrhea is one of the most common symptoms associated with irritable bowel syndrome. It affects more women than men. Infectious diarrhea can affect anyone that comes into contact with the bacteria that can cause the diarrhea. There are multiple different types of infections that a patient can get that can cause diarrhea. The most common infections include C Diff, which is an infection that you get after taking certain antibiotics. Parasitic infections, E-coli, these are all infections that you can get from traveling or coming into contact with someone that had that infection. Other causes of diarrhea include autoimmune disorders such as Celiac disease in which you get an autoimmune antibody to your small bowel from gluten. And that can cause a malabsorptive process, which then causes diarrhea. Increased acid production in patients can cause diarrhea. Any type of GI malignancy such as pancreatic cancer, small bowel cancer, or colon cancer can cause symptoms of diarrhea. So when a patient has diarrhea, you really need to look into the exact cause of it. Other types of autoimmune disorders such as inflammatory bowel disease, Crohn's disease, ulcerative colitis and microscopic colitis, are all some of the common causes of new onset chronic diarrhea. If your diarrhea extends for over four to six weeks, it's something that you definitely need to see either your primary care physician or a gastroenterologist in order to do further testing to find out the exact cause of your diarrhea and to treat it.