left paraumbilcal gnawing pain

Actually I would describe it as discomfort rather than pain. For 3 days now, I've been experiencing persistent gnawing, peristalsis-like left paraumbilical discomfort lasting 2-3 seconds at 1-3minute intervals. At first I thought it was the choco shake that I had that's causing my stomach to act up. I tried taking omeprazole 20 mg (2x) and Hyoscine 1omg (Buscopan) but there was absolutely no change in the character or frequency of the discomfort. I have no changes in bowel movement, no vomiting, fever or abdominal tenderness (direct or rebound) and slightly relieved by voluntary belching. There's just this every 1-3 minute discomfort. No matter what I do, whether I think about it or not, I still feel this peristaltsis-like very bothersome sensation to the left almost epigastric and paraumbilcal area. My medical history: gallbladder polyp & solitary gallstone0.5cm, S/P CS delivery (2005), present medicines (Metformin 500mg & Simvastatin 20 mg at bedtime).  Please advise me as to what I can do about it. Thank you so much.