I have a stabbing, spasm type of pain behind my belly button. I felt a shooting type pain from my left incision to this area over the past week. But today the pain is strictly underneath my belly button and it’s excruciating. Does anybody know what what causes this?

Call your doctor's office. They may want to examine you. An abscess could develop in that area.

I agree see your medical team. General discomfort & muscular pain is too be expected but stabbing, acute pain is not.

It could be an infection. Definitely call your doctor