Q. A 28-year-old web developer presents to the clinic with a 3-month history of intermittent right lower abdominal pain, non-bloody diarrhea (up to five times daily), and significant weight loss of approximately 12 pounds. The pain typically worsens after meals, and he reports occasional night sweats but denies any fever. He mentions a similar episode two years ago that resolved on its own, but the symptoms are more severe this time. He has a smoking history of about a pack a week for the last ten years. His mother has a history of unspecified bowel disease. On physical examination, he appears slightly underweight, fatigued, and uncomfortable. His abdomen is tender in the right lower quadrant, with a palpable mass. Bowel sounds are audible and increased. The perianal inspection shows no fistulas or skin tags. A complete blood count shows a mild anemia with hemoglobin of 11.5 g/dL, an elevated ESR of 42 mm/hr, and a C-reactive protein of 3.5 mg/dL. A stool sample test shows no blood, but fecal calprotectin is elevated at 250 ?g/g. Which of the following is the best next step in managing this patient's condition?