If you have bowel issues all the time, see a gi doctor for a colonoscopy. You may have a food allergy. I had diarrhea for a year with aches and tiredness. Finally went to the gi doctor and found I have a gluten allergy. I swear I feel like a new person now that I figured out why I couldn't stop using the toilet.
There's simply one answer you might have the flu or a cold
you don't say how long you have had diarrhea. And you don't say if you vomit or drink enough water or liquids. If you are dehydrated, you will feel sick and very tired. Diarrhea can do that to you. Also, sodas, coffee and tea will dehydrate you. Many people think that drinking sodas or iced tea is great in the heat of the day... not so. Water is the best choice. If you don't like the taste of water, add a little lemon juice to it.
Hope this information helps you.