I have had ongoing postprandial diarrhea for the past year, and general diarrhea for 5 years prior. i can count on both hands the the amount of normal bowel movements in any given year. is it worth seeing a primary care doctor about this issue?

Absolutely, your primary care doc ideally. While there are a variety of conditions that may account for your symptoms, their duration and possible long term effects on absorption may result in significant deficiencies and aside from the distress itself of using the bathroom after each meal. Keep a log with type of food ingested/ drinks/ supplements and actual symptoms.

Agree with Dr. P. If you have experienced unintended weight loss, it is even more important to see your doctor for an initial evaluation and to ascertain if a GI consult may be warranted. Wish you good health!