Yes, ITP is a cause fo spleen enlargement. Certainly if the spleen is enlarged enough, it can cause the abdominal pain you are describing.
Other tests to evaluate for possible pancreatic cancer would be an ERCP, MRI or endoscopic ultrasound. If this diagnosis is still considered, then you may want to consider these more specialized tests.
If those tests are negative, and the spleen has been excluded as a cause, you can consider tests to evaluate the gallbladder function - which can atypically present with pain on the left side.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Thanks,
Kevin, M.D.