Based on NIH | Can Lisinopril cause diarrhea, and how should I manage this side effect if it occurs?

Lisinopril can cause diarrhea in some people, and there are practical steps you can take to manage it safely. ^[1] Diarrhea is generally considered a mild to moderate side effect, but persistent or severe diarrhea needs attention because it can lead to dehydration and low blood pressure. ^{[1] [2]}

How common and why it matters

• Diarrhea is listed among the more common, non-serious side effects of lisinopril. ^[1] In clinical experience with ACE inhibitors, diarrhea has been reported, though it is not among the most frequent reasons for stopping the drug. ^[3] Even mild diarrhea can lower your body’s fluid and salt levels, which may increase the risk of dizziness or fainting while on lisinopril. ^[2]

When to seek medical advice

• You should contact your clinician if diarrhea is severe, continues for more than a couple of days, or is accompanied by dizziness, fainting, vomiting, or signs of dehydration (such as very dark urine or feeling very weak). ^{[4] [2]} If you develop swelling of the face, lips, tongue, or throat, trouble breathing or swallowing, or unexplained fever these are urgent warning signs and you should seek immediate medical care. ^[1]

Rare but important consideration: intestinal angioedema

• Very rarely, ACE inhibitors can cause angioedema in the intestines, which can present with abdominal pain, nausea, vomiting, and diarrhea; symptoms typically improve after stopping the ACE inhibitor. ^[5] This condition is uncommon but should be suspected if you have recurrent abdominal symptoms without another clear cause while taking an ACE inhibitor. ^[6]

At-home management steps

• Stay hydrated: take small, frequent sips of water or an oral rehydration solution to replace fluids and salts. ^[4] Because diarrhea and vomiting can drop blood pressure while on lisinopril, maintaining fluid intake helps reduce dizziness or fainting. ^[2]
• Be cautious with positions: rise slowly from sitting or lying to reduce lightheadedness. ^[4]
• Gentle diet: consider bland, low‑fat foods (e.g., bananas, rice, toast) until symptoms ease; avoid alcohol and very spicy or fatty foods during active diarrhea. ^[4]
• Monitor symptoms: track how often you have loose stools, any associated dizziness, and your fluid intake; this information helps your clinician assess severity and next steps. ^{[4] [2]}

Medication and dosing considerations

• Do not double up on lisinopril if you miss a dose; if it’s close to your next dose, skip the missed dose and resume your regular schedule. ^[7] If diarrhea is ongoing or you feel lightheaded, a clinician may suggest checking your blood pressure more frequently and possibly adjusting your lisinopril dose. ^{[4] [2]} If you take a combination pill with a diuretic (water pill), diarrhea can compound fluid loss, so prompt clinician guidance is especially important. ^[8]

Preventing complications

• Keep fluid intake adequate, especially in hot weather or during exercise, to prevent dehydration and low blood pressure while on lisinopril. ^[4] Diarrhea, vomiting, and heavy sweating can each contribute to a drop in blood pressure and increase the chance of feeling faint. ^[2]

Bottom line

• Diarrhea can occur with lisinopril and is usually mild, but ongoing or severe symptoms warrant medical review to prevent dehydration and low blood pressure and to rule out rare complications. ^{[1] [4]} With hydration, cautious activity, and timely clinician input, most people can manage this side effect safely. ^{[4] [2]}