My mother has stomach pain-ongoing for weeks, sometime really intense, and she has diarrhea sometimes as well. she is 63, is this really concerning?cancer?

Need endoscopy: Intense pain and change in bowel movements requires gastroenterology consult. Colonoscopy is recommended every 3 - 5 years after age 50; and with your Mom's symptoms recommend this as well as EGD (esophogealgastricdueodenalscope); otherwise known as an upper GI endoscopy. Please consult with PCP for gastro consult.

Exam needed: Persistent and occasionaly intense abdominal pain for weeks certainly warrant investigation. Since you don't describe the type and location of the discomfort, it's not possible to suggest possible causes. It doesn't necessarily mean malignancy but in a 63 year old person, it can't be excluded. Please get her prompt medical attention.