I am afraid I don't know what the problem is, but I have had all the symptoms... so if you find out let me know! All the best.
The diarrhea could be dehydrating you, causing the rest of the symptoms. Increase you water intake, add some juice and a couple of small glass of gatorade can do wonders.
I saw a report on TV this morning that said that lots of people are finding out that they are allergic to Soy products. But the number one symptom was nausea.
A weak, lightheaded feeling could be from anemia. You could have a deficiency of folic acid.
Have you had your blood sugar levels looked at? I don't know about the mild stomach discomfort, but the other symptoms sometimes indicate an imbalance in sugar levels.
sounds like it could be diverticuitis or irritable bowel syndrome usually a blood test can tell if you are anemic which would also cause tireness
i had chronic diarrhea due to IBS for 5 weeks which caused me to feel weak, tired and shaky ..i started taking citrucel (a fiber) daily at the advice of my GI and the diarrhea was gone in 3 days!!
BINGO....low-blood sugar!
Do you also feel "drained"; have poor memory; feel "spacey" or "unreal"; numbness, burning or tingling; insomnia; muscle aches; muscle weakness; attacks or anxiety or crying; cold hands or feet and/or chilliness?
Check into Candida Related Complex caused by Candid albicans infection.