A patient who takes several antidepressants and cetirizine (Zyrtek) complains to the nurse about experiencing hemorrhoids as a result of chronic constipation. Which instruction should the nurse include in patient teaching for initial therapy?

For a patient experiencing constipation-related hemorrhoids — particularly one whose constipation is likely medication-induced by anticholinergic effects from antidepressants and the antihistamine cetirizine — the initial, safest, and most conservative approach is to increase fluid intake to approximately 2 liters per day. Adequate hydration softens stool by increasing the water content of feces, reducing straining during defecation and thereby relieving pressure on hemorrhoidal tissue. This non-pharmacological first step follows the principle of starting with the least invasive intervention. Lactulose (option D) is an osmotic laxative appropriate for hepatic encephalopathy and more severe constipation, but it causes significant gas and cramping and is not first-line for simple constipation. Senna (option B) is a stimulant laxative; while effective, it is not the initial therapy of choice when a simple lifestyle measure can address the problem first. Glycerin suppositories (option A) work locally in the rectum and can soften stool at that level, but they are a step beyond basic hydration and are not the initial recommendation. Increasing fluid intake remains the cornerstone of initial constipation management, especially when medication-induced causes are identified.