hi i had gone through your query and understand your concerns. i would come up with two most possibilities to fit your condition .these include
1.first possibility is,gas trouble (or APD ACID PEPSIC DYSPEPSIA
).irregular dietary habits,modern lifestyles (drinking,smoking
,etc),EXCESSIVE USE OF PAIN KILLERS,ANTIBIOTICS,STEROIDS
for even minor complaints, CURRY,HURRY,,NIGHT WATCHING,SUPPRESSED STRONG EMOTIONS are the main causative factors.
2.second possibility is,RENAL STONES;confirm with ultrasound
scanning for KUB
I hope this is helpful for you, thank you