Hi, Thanks for using HCM.
Since your gall bladder
was removed, there wont be any storage of bile that to be released with food. So this may cause you stool which smells like chemicals.
But for pain you need to get done USG abdomen and pelvis, stool examination with LFT once to know if any problem there.
Dairy products and chocolate contain more of oil and fat. So there wont be adequate bile released for its digestion and hence you may be getting this discomfort.
For pain now you can take NSAID
with anti spasmodic drug and drink plenty of water. Consult your doctor for further management. Hope I answered your question.
Feel free to ask me if you have any further queries.
Wish you good health. Take care.