A28-year-old man presents with complaints of diarrhea, fecal urgency, and weight loss. his stool is light colored and malodorous, and it tends to float and be difficult to flush. he has also noted tender, red bumps on his shins and complains of pain and stiffness in his elbows and knees. sigmoidoscopy reveals discontinuous, granulomatous lesions; no blood is detected in his stool. which of the following diagnoses would his care team first suspect?
a. crohn disease
b. ulcerative colitis
c. diverticulitis
d. colon cancer