2013 sg3 student

DIARRHEA MINI-CASES

Small Group 3November 25, 20132pm

Case 1: A 32 year old man with Crohns disease involving his terminal ileum and right colon underwent surgical resection of 50 cm of ileum and 25 cm of right colon with primary anastomosis last year for recurrent bouts of intestinal obstruction. He now presents with watery diarrhea 5-7 times daily. He feels well generally and denies weight loss. There was no evidence of active Crohns disease at colonoscopy a few months ago. He is taking no medications at this time and has no allergies. Social history and family history are non-contributory. On physical exam, he is a healthy-appearing man in no distress. Vital signs are normal. His physical exam is only remarkable for a well-healed laparotomy scar; he has no tenderness on abdominal exam and on rectal exam his stool is brown.

Stool examination reveals the following: no white blood cells, ova and parasites negative, C. difficile toxin negative, culture negative. Stool osmolality 290 mOsm/kg H2O (NL 290), Na+ 97 mmol/L (NL 30), K+ 36 mmol/L (NL 75).

Questions:1. What is the most likely cause of his diarrhea?

2. Explain the etiology of his diarrhea. Could his surgical procedure have contributed to his diarrhea? If so, by what mechanism?

3. Calculate the stool osmotic gap. Is this a secretory or osmotic diarrhea?

4. Will fasting ameliorate or exacerbate this patients diarrhea?

5. What is the treatment for this condition?

Case 2: Additional history the patient improves with therapy. 6 months later, he then develops another small bowel obstruction, this time requiring resection of 60 cm of his remaining distal small bowel. He recovers from his surgery but notes the development of recurrent diarrhea with foul smelling stools; this does not improve with the therapy that had worked earlier. In addition, he was recently in the emergency room after he developed acute onset right flank pain which he describes as the worst pain of his life. He was diagnosed with a kidney stone which he eventually passed.

Questions:1. What is the cause of his diarrhea? Why is it no longer responding to prior therapy?

2. What is the most likely type of kidney stone in this case and what is the etiology of these stones?

3. What are some other complications of losing large amounts of ileum?

Case 3: A 20 year old man visits his primary care physician complaining of abdominal pain, flatulence, diarrhea, bloating and abdominal distension. His symptoms have been present intermittently for the past 2 years. His symptoms occur only after meals, particularly after eating ice cream. He denies nocturnal diarrhea, blood in the stool, weight loss, fever, recent travel, or antibiotic use. He is taking no medications (prescription or over-the-counter) and has no allergies. He does not smoke or drink alcohol and his family history is non-contributory.

On physical exam, he is a well-appearing man in no distress. His vital signs and physical exam are normal, including a normal rectal exam.

Stool examination reveals the following: no white blood cells, culture no growth, ova and parasites negative, C. difficile toxin negative. Stool osmolality 290 mOsm/kg H2O, Na+ 37 mmol/L, K+ 42 mmol/L

Questions:1. What is the most likely cause of his diarrhea?

2. What is the mechanism for his diarrhea?



5. What is the best test for this disorder?

6. What are some other tests of carbohydrate malabsorption?

Case 4: A 27 year old woman presents to her primary care physician with severe diarrhea. She says that her symptoms began after a recent trip. Two days after she arrived home, she had the acute onset of loose watery, non-bloody stools, up to 8 times daily. She also complains of nausea and vomiting of clear fluid. She has not been able to keep anything down, not even water or Gatorade. She has some abdominal cramping before her bowel movements, but otherwise she denies any localized abdominal pain. She denies fever or recent antibiotic use. She traveled to New Orleans on business and ate at a popular seafood restaurant.

On physical exam, she appears mildly ill with sunken cheeks. She is afebrile with normal respirations. Her heart rate is 110 bpm and BP 100/60 supine; on standing, heart rate goes to 130 bpm and BP 85/60. Her physical exam is remarkable for dry mucus membranes; on abdominal exam, she has mild, non focal tenderness with no rebound or guarding; rectal exam reveals watery stool.

Stool examination reveals the following: no white blood cells, C. difficile toxin negative, stool osmolality 290 mOsm/kg H2O, Na+ 98 mmol/L, K+ 40 mmol/L

Gram stain is shown below:

Questions:1. What is the most likely cause of her diarrhea?

2. What is her major risk factor for diarrhea?

3. What is the mechanism for her diarrhea?



6. What should be the first step in management of this patient?

Case 5: A 24 year old woman presents with 12 days of nausea, crampy abdominal pain, bloating and watery diarrhea; loperamide has not helped. She denies any fevers, vomiting, weight loss, blood in the stool, travel, or recent antibiotic use. Her past history is unremarkable. She works at a daycare center, taking care of 15 toddlers. She denies tobacco or alcohol use, and her family history is non-contributory.

On physical exam, she is an ill-appearing young woman in moderate distress. Her vital signs are normal. Her exam is remarkable for abdominal distension and hyperactive bowel sounds; her abdomen is nontender and on rectal exam she has loose stool.

Stool examination reveals the following: no white blood cells, C. difficile toxin negative. Ova and parasite evaluation reveals the image below:

Questions:1. What is the cause of the patients symptoms?

2. What is the pathogenesis of this patients diarrhea?

3. What are the risk factors for this entity, and does this patient have any?

4. How is this entity diagnosed?

5. What is the treatment for this entity?

References:

Handbook of Gastroenterology, Yamada et al., Lippincott Williams & Wilkins, 2nd edition, 2005, Chapter 12, pages 76-86; Chapter 38, pages 298-308; Chapter 39, pages 308-313; Chapter 69, pages 555-560.

Sleisenger and Fordtrans Gastrointestinal and Liver Disease, Saunders, 8th edition, 2006, Chapter 9, pages 159-176; Chapter 101, pages 2277-2301; Chapter 106, pages 2414-2428. Available online at Calder.

Case 4 image: http://microbewiki.kenyon.edu/images/thumb/2/2a/Gram_stain.jpg/250px-Gram_stain.jpg

Case 5 image:http://www.occc.edu/biologylabs/Documents/Zoo/Retortamonada.htm

Objectives:1. Explain the mechanism by which various types of diarrhea occur.2. Understand the pathophysiology of the complications of malabsorptive diarrheal syndromes. 3. Understand the concept of osmotic versus secretory diarrhea and be able to differentiate the two based on clinical features and stool studies.