It's been 16 days since i have had a substantial bowel movement. it's been 6 days since i have passed anything. however, i am still passing gas. er?

It depends...: Glad that you are passing gas. Some people are constipated for days on end. If you are having and abdominal pain, nausea, or vomiting this could be a sign of ileus or obstruction. Is there any change in appetite weight loss? How often do you normally go? Tough to say if this is simply a situation that can be helped with increasing fiber or adding a laxative.

Yes. Evaluate cause.: Best case: It may be your diet an you can use a stool softener or enema. Worst case: It may be a small bowel obstruction that needs surgery. Either way you should visit the ER or Urgent Care to be evaluated. Imaging studies may be needed.