Microscopic Colitis with Case

00:00 Let's move to our next case now.

00:03 A 65-year-old woman presents complaining of 5 months of watery diarrhea.

00:08 She has 5-6 watery bowel movements a day with a few episodes at night.

00:13 She has no weight loss, bloody stool, fevers or abdominal pain.

00:17 Her only medication is amlodipine which she takes for hypertension.

00:21 On exam, she has normal vitals, an unremarkable abdomen and her rectal exam is normal.

00:28 Colonoscopy shows a normal colon.

00:30 And biopsies of the colon are taken that show many lymphocytes infiltrating the lamina propria.

00:38 What is the most likely diagnosis? So we'll point out that she has 5 months, so that's chronic diarrhea.

00:46 She does have episodes of diarrhea at night which is a clue that suggests a secretory diarrhea.

00:52 And she has importantly no alarm symptoms In addition, the gross appearance of the colon on colonoscopy is normal.

01:03 The next thing we can look at is the lymphocytes infiltrating the lamina propria on a random biopsy for colon Putting this together, the gross appearance which is normal with lymphocyte infiltration on a random biopsy should hint at a diagnosis of microscopic colitis.

01:22 So, her biopsy results are consistent with the diagnosis of lymphocytic colitis We'll talk about that in more detail next.

01:30 So, lymphocytic colitis is a type of microscopic colitis.

01:36 This is a chronic inflammation of the colon.

01:39 Patients tend to present with chronic watery non-bloody diarrhea It tends to affect mostly middle-aged women.

01:48 And as with our case, they often have a normal appearance on colonoscopy.

01:54 However, on biopsy, you will find two subtypes, either lymphocytic colitis or collagenous colitis The diagnosis is made purely by the biopsy.

02:05 And these patients are treated with antidiarrheals and corticosteroids Thank you very much for your attention.