The most commonly reported side effects with Celebrex were:

• indigestion
• diarrhea
• abdominal pain

In some rare cases, more serious stomach problems such as bleeding can occur, with no warning. If burning stomach pain, black, tarry bowel movements or vomit that looks like blood or coffee grounds manifest, stop taking Celebrex and call a doctor. It's important to keep in mind, however, that most people taking Celebrex do not stop doing so because of its side effects.