Which of the following statements is INCORRECT about the pharmacologic treatment of Crohn's disease?

Metronidazole is effective in the treatment of Crohn's disease.

Sulfasalazine is effective in the treatment of mild Crohn's disease.

Thiopurines can be used in the treatment of Crohn's disease for their steroid-sparing effects.

Avoid NSAIDs in the treatment of Crohn's disease because they may exacerbate disease.