American Board of Internal Medicine (ABIM) Certification Practice Exam

Which condition is indicated by diarrhea with features of impaired motility?

1. Diabetes mellitus

2. Cholera

3. Pancreatic insufficiency

4. Whipple disease

The correct answer is: Diabetes mellitus

Diarrhea with features of impaired motility is often associated with conditions that lead to dysregulation of the gut's normal propulsion mechanisms. In the context of diabetes mellitus, especially those cases with autonomic neuropathy, patients can experience gastrointestinal issues such as gastroparesis. This delayed gastric emptying can lead to diarrhea that may appear inconsistent or poorly formed, reflecting the impairment in movement through the digestive tract. In diabetes, the effects of autonomic neuropathy can disrupt normal bowel motility, leading to symptoms that include both constipation and diarrhea. Therefore, the association of diabetes mellitus with impaired motility resulting in diarrhea makes it a plausible diagnosis for this clinical scenario. Other conditions like cholera characterize watery diarrhea due to infectious processes and do not primarily involve impaired motility, whereas pancreatic insufficiency is typically associated with steatorrhea due to malabsorption rather than motility issues alone. Whipple disease is an infectious etiology manifesting with malabsorption and may include diarrhea, but it does not specifically highlight impaired motility as its primary feature.