Since how long are you having these symptoms ?
Is there any associated acid reflux ?
Any associated burning while urination ?
Is the pain located on the back side ? Does this radiate to the lower abdomen ?
Also there can be associated hydronephrosis ( It is distention and dilation of the renal pelvis, usually caused by obstruction of the free flow of urine from the kidney.) which can also cause dull pain .
Even main side effects of exenatide(Byatta) use are gastrointestinal in nature, including indigestion, nausea, and vomiting.
So it is advised to undergo EKG,Urinalysis, Ultrasound (abdomen) as per said by doctor .
As it requires proper clinical examination.
If your pain 'll get severe then i suggest you to consult your regular doctor for further evaluation and management.
I hope this helps.
The region of the abdomen you describe pain is called as left hypochondrium .
It is essential to rule out various differential diagnosis of left hyponchondrium pain by relevant medical investigations as mentioned above ..
Gastric ulcer/Gastritis can indeed be a possibility in your case .
Also some times a lesion in the lungs can cause reffered pain in the area you describe .
After relevant clinical examination your doctor may advise an ultrasound abdomen ,chest X-Ray (P.A View).
If there is any periodicity of pain and food Gastritis can be a possibility in your case .
I hope this helps
Spleen ,stomach are situated in this area .