Colonic Motility Dysfunction: 3 Cases on Cause, Effects, Treatment

Case #1. A 28-year-old woman presents with postprandial diarrhea and bloating. Which of the laboratory abnormalities above is most likely to be present in this patient?

Answer: D. Decreased serum vitamin B12. Small intestinal bacterial overgrowth (SIBO) can occur in cases of surgically altered gastrointestinal anatomy, diabetes mellitus, and several other predisposing conditions.

#2. A 39-year-old woman presents for evaluation of chronic constipation. You make the shared decision to start linaclotide. Which of above is the mechanism of action for this medication?

Answer: D. Guanylate cyclase-C agonist. Linaclotide works as an agonist at the guanylate cyclase-C receptor, resulting in increased colonic water and assisting with transit.

#3. An otherwise healthy 25-year-old man presents for evaluation prior to a trip to rural West Africa. Data to support prevention of traveler’s diarrhea when the drug is taken daily is strongest for which of the above?

Answer: C. Rifaximin. Rifaximin has been shown to reduce the incidence of traveler’s diarrhea if taken once-a-day during a trip and continued for an additional 2 days after the travel is complete.