Can sulfasalazine get rid of colon stenosis'?

No: Sulfasalazine is a class of drugs used to treat inflammation in the colon. Stenosis, or stricturing is usually a sign of severe disease. This will require a stronger class of medication (such as immunomodulator or biologic) or surgery to treat. If it is a stenosis in the setting of ulcerative colitis, this is more concerning and surgery and usually treated by surgery.