Hello, my name is Joe Vicari. I will be one of the faculty members at this year's ASGE APP course, and I'd like to welcome you back to our second APP video question of the week. So let's jump into it. A 40-year-old white female with celiac disease has experienced non-bloody watery diarrhea for eight weeks. No other symptoms and not on any medication. She is strictly, and she's very adamant about this, strictly adherent to a gluten-free diet. Celiac serology performed one week ago was normal. Which of the following is the most likely cause of her diarrhea? Ulcerative colitis, medication-induced diarrhea, celiac disease, or microscopic colitis? If you need more time, I'll give you a moment to pause the video, and when you're ready, go ahead and restart, and you can listen to the answer. The correct answer is number four, microscopic colitis. Number one, ulcerative colitis does not fit. The patient has non-bloody diarrhea, no abdominal pain, no weight loss, and otherwise feeling well. Medication-induced diarrhea doesn't make sense. She's not on any medication. Celiac disease is a possibility, but she's a very reliable patient, strictly adherent to her gluten-free diet, and her serology, although not perfect, was normal a week ago. Microscopic colitis is the correct answer, as I said. Patients with celiac disease have a higher incidence of microscopic colitis. Microscopic colitis is more common in women than in men. There are two types, collagenous colitis, which accounts for most of the predominance in women, and lymphocytic colitis, which can be seen a little more frequently in men, and a little more equal with women. The diagnosis is made by history. They typically have watery diarrhea, more than three bowel movements. The diagnosis is made at histology. Collagenous colitis has an expanded basement membrane, and lymphocytic colitis has lymphocytes scattered among different layers of the colon under the microscope. Medications have been associated with microscopic colitis, specifically NSAIDs and PPIs. Treatment is typically to control the diarrhea. In patients with diarrhea less than three times a day, a simple antidiarrheal, such as Imodium or Limodil, and even Pepto-Bismol can help. Those with more significant diarrhea, more than three times a day, typically Budesonide is used. That's a very quick review of microscopic colitis. The main take-home point here is those patients with celiac disease who have stable disease and have decompensation, please remember to consider microscopic colitis. Thank you, and I look forward to the next question next week.

celiac disease

non-bloody watery diarrhea

microscopic colitis

gluten-free diet

celiac serology