There are many potential causes of sharp pain just above the belly button, but some of the most common ones include:

- Gastritis: This is an inflammation or irritation of the lining of the stomach. It can cause a gnawing or burning pain in the upper abdomen that may worsen after eating.

- Ulcers: An ulcer is a break in the tissue that lines the stomach or intestine. Ulcers can cause a sharp, stabbing pain in the upper abdomen.

- Gallstones: Gallstones are stones that form in the gallbladder. They can cause a sudden, intense pain in the right upper abdomen that may radiate to the back.

Please seek medical attention if your pain is very severe and stops you from doing normal daily activities.