Ambien and upset stomach

This is a follow up message to 'Marika''s message; I took Stilnox on and off 2 weeks ago, and then there are some unwanted side effect which arrouse my attetion of finding more about Stilnox (ambien) side effect. I had experienced S +S of peptic ulcer which strong acid reflux occured before and after I took the meal. Also, I had noticed some irregularity of my heart beats. Four days after I stop taking it, the S+S started to disappeared and my stomach is starting to feel at ease. Is there any possibilities which we might have the chance to understand a bit more about the pharmacodynamics and safety features related to this medication.
Man!! the upset stomach really upset me...

I have been taking ambien on and off for two years on the advise of my doctor (neuroligist) Ever since I had lower back surgery I have developed this irritable and shaky leg syndrome, which causes me not to sleep. I have been taking all kinds of pain medicine, which i seem to have alergic reactions to most (Hives, upset stomach etc.)
The only thing that has helped me sleep is Ambien. However, I have noticed that after I eat, my stomach really hurts and i get heavy palputations (In the stomach area).
About 6 weeks ago I was rushed to emergency beacause of stomach pain, bowel movement was black ( thought I had a bleeding ulcer) But they found nothing.
Could this be the side affects of Ambien?