When lactulose 30 mL four times daily is ordered for a patient with advanced cirrhosis, the patient complains that it causes diarrhea. The nurse explains to the patient that it is still important to take the medication because the lactulose will result in which outcome?

Choice A rationale Lactulose is a synthetic disaccharide that is not absorbed in the small intestine, but it does not have properties that prevent gastrointestinal bleeding. Bleeding in cirrhosis is usually caused by esophageal varices or coagulopathy. Normal hemoglobin levels are 12 to 18 g/dL. While lactulose manages hepatic encephalopathy, it cannot address the portal hypertension or clotting factor deficiencies that lead to hemorrhage. Prevention of bleeding typically requires beta-blockers or endoscopic banding rather than the administration of osmotic laxatives. Choice B rationale Lactulose is used in cirrhosis to lower blood ammonia levels, which are normally 15 to 45 mcg/dL. It works by acidifying the colon, converting ammonia into non-absorbable ammonium, and then excreting it through stool. This process prevents ammonia from crossing the blood-brain barrier, thereby improving neurological status and reversing symptoms of hepatic encephalopathy like confusion or asterixis. Even if it causes diarrhea, the medication is vital for maintaining cognitive function and preventing life-threatening hepatic coma. Choice C rationale While lactulose is an osmotic laxative that pulls water into the bowel, its primary therapeutic purpose in cirrhosis is not fluid loss or the treatment of edema. Fluid volume overload in liver failure is typically managed with diuretics like spironolactone or furosemide. Normal serum potassium is 3.5 to 5.0 mEq/L. Although the patient may lose some fluid through diarrhea, the clinical goal is the chemical entrapment and elimination of nitrogenous waste products to protect the central nervous system. Choice D rationale Lactulose does treat constipation by increasing the osmotic pressure in the lumen of the bowel, but for a patient with advanced cirrhosis, this is a secondary effect. The primary medical indication is the management of hyperammonemia. In this specific context, diarrhea is actually a sign that the medication is working to evacuate the colon. The nurse must explain that the goal is to have two to three soft stools per day to ensure sufficient ammonia clearance.