I have noticed 6 inch + thin light brown "strings" in the toilet for a few months. i have chronic diarrhea but big pain increase. thanks?

Parasitic infection: The symptoms you describe suggest a parasitic infection. You should see your doctor for evaluation for infection.

'Strings' need eval: Strings in the stool could be anything as simple as undigested vegetable matter to a parasite. Since this is associated with chronic diarrhea and now abdominal pain I think you need to see a doctor. You may need to get a stool sample to test. Either way getting pain and chronic diarrhea isnt normal. Get evaluated. .