A 40-year-old patient complains of chronic pain abdomen and diarrhea. She gives history of passing 22-25 stools per day. She also complains of weight loss. On examination, patient is noted to have mild fever with right lower quadrant tenderness. Lower GI endoscopy was done with the following findings: HPE reveals the following findings: An intern posted in the medicine ward makes a list of differential diagnosis for this patient. Which of the given option is most likely the diagnosis?