###Human: What are the causes of diarrhea and nausea every morning, with terrible sinus headache? ###Assistant: Hello. So you have two issues, one is your sinusitis, and the other is diarrhea. Gastritis is probably antibiotic associated, so you need to discuss with your doctor and change the antibiotics that are causing your diarrhea. I would suggest the following for your gastric problems. For sinusitis along with antibiotics I would suggest you try the following. For a headache, you can have Paracetamol or Ibuprofen whenever needed. If it is not helping, then you need to discuss with your local doctor for a short course of oral steroids. Consult your specialist doctor, discuss with him or her and start the medication after their consent. Get back if you have any doubts. For further information consult an internal medicine physician online -->