A 22-year-old man with Crohn's disease comes to the physician complaining of diarrhea. Three months ago, he had surgery due to small-bowel obstruction that involved ileal resection with sparing of the ileocecal valve. Since the surgery, he has had 4 or 5 loose bowel movements a day. The diarrhea disrupts his daily life and interferes with his graduate studies. The patient has no fever, abdominal pain, vomiting, or weight loss. He had a perianal abscess treated with oral metronidazole 7 months ago.
Vital signs are within normal limits. Physical examination shows a well-healed abdominal scar. There is no abdominal tenderness or palpable mass. The perirectal skin is intact.
Laboratory results are as follows:

Which of the following is most likely to improve this patient's symptoms?

Question

A 22-year-old man with Crohn's disease comes to the physician complaining of diarrhea.  Three months ago, he had surgery due to small-bowel obstruction that involved ileal resection with sparing of the ileocecal valve.  Since the surgery, he has had 4 or 5 loose bowel movements a day.  The diarrhea disrupts his daily life and interferes with his graduate studies.  The patient has no fever, abdominal pain, vomiting, or weight loss.  He had a perianal abscess treated with oral metronidazole 7 months ago.
Vital signs are within normal limits.  Physical examination shows a well-healed abdominal scar.  There is no abdominal tenderness or palpable mass.  The perirectal skin is intact.
Laboratory results are as follows:

Which of the following is most likely to improve this patient's symptoms?

Quizplus · Accepted Answer

Ileal resection leads to vitamin B12 deficiency, bile salt malabsorption (subsequent malabsorption of fats and fat-soluble vitamins), and secretory diarrhea. The secretory diarrhea is due to malabsorbed bile acids entering the colon causing colonic stimulation; cholestyramine lessens this process by binding the bile acids. Treatment for patients with ileal resection also involves supplementation of vitamin B12 and other fat-soluble vitamins. (Choice B) Lactose intolerance presents with abdominal bloating, cramping, and bulky diarrhea associated with intake of dairy products. Although patients with Crohn's disease or ileocecal valve resections (and subsequent small intestinal bacterial overgrowth) are at increased risk for lactose intolerance, this patient's ileal resection and symptoms favor bile salt malabsorption over lactose intolerance. (Choices C and D) Mesalamine can be considered for postoperative prophylaxis in patients with mild to moderate Crohn's disease and in those who may have responded to it before surgery. However, this patient's symptoms and normal inflammatory markers are less consistent with Crohn's flare. Similarly, he does not require prednisone therapy. (Choice E) Probiotics may be helpful in some patients with pouchitis (fever, abdominal pain, tenesmus, diarrhea, and hematochezia), ulcerative colitis, and certain infectious diarrheas. However, they are not as useful in patients with bile salt malabsorption. Educational objective: Cholestyramine is used to treat diarrhea due to bile salt malabsorption from ileal resection. __________ References: Bile acid malabsorption. (http://www.ncbi.nlm.nih.gov/pubmed/17298762)

A 22-Year-Old Man with Crohn's Disease Comes to the Physician