hi welcome to HCM
-i had gone through your query and understand your concerns. i would come up with two possibilities for your complaints.
1.the first one for stomach complaints may be PEPTIC ULCER;upper gastro intestinal endoscopy
may confirm the diagnosis.
the possible causes include
-taking non steroidal anti inflammatory drugs,
2.second possibility for wrist and finger pains may be RHEUMATOID ARTHRITIS;
it is an autoimmune disease
confirm with blood test
for elevated RA factor,CRP,ASO trite,and ESR.
wishing you good health