A 55-year-old man presents complaining of frequent foul-smelling stools, excess gas, 10-pound weight loss, and unsteadiness of gait. His past history includes multiple prior episodes of small intestinal obstruction arising from adhesions from abdominal surgery for trauma. He still complains of occasional periumbilical pain after eating, and has generalized aches and pains and chronic soreness around his mouth. He takes a proton pump inhibitor for gastroesophageal reflux. Apart from his previous scars, his abdominal exam is normal. He has absent ankle jerks and he is unable to maintain an upright posture gait with his feet together once he closes his eyes. His investigations reveal stool fat levels of $15 \mathrm{~g} / 24$ hours. His labs are notable for macrocytic anemia, an elevated alkaline phosphatase, and a low serum albumin. CT of his abdomen reveals some mildly dilated small bowel loops. Which of the following statements are incorrect?

Correct Answer: D

Rationale: He has fat malabsorption and steatorrhea secondary to bacterial overgrowth from intestinal stasis arising from his adhesions. Bacterial overgrowth leads to vitamin B12 deficiency from bacterial consumption of B12. His B12 deficiency has caused him to develop subacute combined degeneration of the cord with a positive Romberg's sign, stomatitis, and evidence of a peripheral neuropathy. Folic acid levels may increase as folate is produced by luminal bacteria. The reduction in gastric acid by proton pump inhibitors increases intestinal bacteria and is probably exacerbating bacterial overgrowth in this setting. Acid is also needed to release protein-bound vitamin B12 from food, and individuals who take PPIs absorb less vitamin B12 from food but rarely to such an extent that it leads to vitamin B12 deficiency. Many patients with small bowel bacterial overgrowth have mildly abnormal intestinal villi, which occur secondary to the effect of excess bacteria. Since his bacterial overgrowth is related to his anatomy, he will require regular cycles of antibiotics.

Correct Answer: A

Rationale: This patient has stage 2 hepatic encephalopathy. He should be treated with lactulose despite the normal ammonia level because this test is neither sensitive nor specific as a marker for encephalopathy. A low-protein diet is also recommended. All potentially nephrotoxic (e.g., NSAIDs, gentamicin) or sedating (e.g., lorazepam) medications should be avoided. Acetaminophen should be avoided as well.

Correct Answer: A

Rationale: The urea breath test detects H. pylori by measuring urease activity, which is crucial for diagnosing and managing PUD caused by this bacteria.

Correct Answer: B

Rationale: Clear fluids and a light diet can soothe the stomach and reduce nausea without exacerbating PUD symptoms.

Correct Answer: C

Rationale: A bland diet minimizes irritation and supports healing in a recovering bleeding ulcer.