Pains in stomach with small stool

Sex: Male Age:22
Diet: no citric acid pop for 7 months, no alcohol, or smoking.

I have had terrible acid reflux for around 7 months. Then the pain got a lot worse the symptoms matched a stomach ulcer. One night after eating pasta I was in so much pain I went to the ER. I went for an upper G.I series x-ray, and an ultrasound.

The ultrasound found nothing, and I didn't receive a call for the upper G.I test.
Before the test I was prescribed losec. I have been taking this medicine for two weeks. Today was my last day

I Now have no appetite from 8am till 6pm so far, and I have been having trouble with my stool...it's very small.

I go to the washroom more often, and just tiny bits come out.

Is this a symptom of the medicine?

I have had this small stool for a while, and I am very worried.



Thank you