Can Taking Benadryl Help Relieve IBS Symptoms?

Treating IBS Symptoms With Benadryl

Irritable bowel syndrome (IBS) is a common disorder affecting the large intestine. Symptoms include abdominal cramping, bloating, diarrhea, and constipation. While not life-threatening, IBS can greatly impact one's quality of life. Many people turn to over-the-counter medications like Benadryl to help relieve their IBS symptoms. But is taking Benadryl for IBS an effective and safe treatment option?

How Benadryl Works

Benadryl contains the active ingredient diphenhydramine, which is an antihistamine. Antihistamines work by blocking the effects of histamine in the body. Histamine is a chemical that is released by the immune system during allergic reactions. It causes symptoms like itching, sneezing, and runny nose.

In addition to its antihistamine effects, Benadryl also has anticholinergic properties. Anticholinergic medications block the action of acetylcholine, which is a chemical messenger in the body. This blocking effect can help dry up excess bodily fluids and relax muscles.

Benadryl for IBS Diarrhea

For those with IBS who mainly struggle with diarrhea, Benadryl may be helpful in reducing the frequency of bowel movements. The anticholinergic properties can slow down contractions in the intestines, allowing more time for water absorption. This leads to firmer, less frequent stools.

One study found taking 25mg of Benadryl 30 minutes before meals helped reduced stool frequency and urgency in diabetic patients with diarrhea. However, the effects of Benadryl on diarrhea specifically related to IBS have not been extensively studied.

Benadryl for IBS Pain and Cramping

By relaxing intestinal and abdominal muscles, Benadryl may also ease some of the painful IBS cramping. The diphenhydramine binds to receptors in smooth muscle tissue, causing the muscles to loosen up. This helps improve painful spasms and cramps.

According to one report, taking 50mg of diphenhydramine significantly reduced abdominal pain in chronic pancreatitis patients. The pain-relieving effects were noted within an hour of taking the medication. More studies are still needed, but Benadryl shows promise for relieving IBS cramping as well.

Other Benefits of Benadryl for IBS

In addition to possibly helping with diarrhea and pain, Benadryl may provide other benefits for those with IBS including:

• Improves sleep quality - Stress can worsen IBS, and poor sleep puts more stress on the body. The drowsiness side effect of Benadryl can promote better sleep.
• Alleviates anxiety - Anxiety goes hand-in-hand with IBS. The calming effect of Benadryl may ease nerves and anxiety.
• Reduces muscle spasms - Smooth muscle spasms play a role in IBS pain and cramping. Benadryl can reduce muscle contractions.
• Dries up mucus - Excess mucus discharge can occur with IBS. The drying effect of Benadryl helps reduce mucus.

Risks and Side Effects

While Benadryl may help tame some difficult IBS symptoms, there are also risks and side effects to be aware of when using antihistamines like Benadryl long-term. Potential side effects include:

• Drowsiness - This can impair driving and doing other tasks requiring alertness.
• Urinary retention - Difficulty fully emptying the bladder may lead to urinary tract infections.
• Constipation - Especially concerning for those prone to IBS-related constipation.
• Confusion - Older adults are at higher risk for delirium-like effects.
• Nausea - Antihistamines slow gastric emptying and may cause an upset stomach.
• Dry mouth - This uncomfortable symptom increases risk for cavities and gum disease.

These unwanted anticholinergic effects can be made worse by taking Benadryl long-term. It is intended only for short-term, occasional use. Using Benadryl daily on an ongoing basis is not advised due to the side effects as well as the potential for dependence and tolerance to develop over time.

The Link Between Antihistamines and C. difficile Infection

There is also some concern over antihistamine medications like Benadryl increasing the risk for C. difficile infection when used long-term. C. difficile, often referred to simply as C. diff, is a bacteria that causes inflammation and damage to the large intestine, resulting in severe, persistent diarrhea.

How Antihistamines May Contribute to C. diff Infection

Research shows that medications reducing stomach acid may promote the growth of C. diff bacteria and increase risk for infection. Stomach acid acts as an important defense mechanism that kills microbes entering the digestive system.

When acid production is lowered, ingested bacteria and spores are able to survive the acidic conditions of the stomach and pass intact down into the intestines. This allows C. diff and other problematic pathogens to proliferate and cause infection when there is not enough stomach acid to keep their numbers in check.

As anticholinergic medications, antihistamines like Benadryl indirectly lower stomach acid secretion. By blocking acetylcholine, less gastrin is released and less stomach acid gets produced. One study found this reduction in gastric acidity persisted for up to 12 hours after taking just a single 50 mg dose of Benadryl.

Risk Factors for C. Difficile Infection

Certain factors already increase an individual's risk for developing an intestinal infection like C. diff. Using antihistamine medications can add to that risk. Known risk factors include:

• Age 65 years or older
• Taking stomach acid-suppressing medications - Antihistamines, PPIs, H2 blockers
• Hospitalization or recent surgery requiring antibiotics
• Inflammatory bowel diseases - Crohn's, ulcerative colitis
• Immunocompromised state
• Gastrointestinal surgery leaving slow motility
• Kidney disease

Those with IBS who regularly take medications that reduce gastric acid to help control their symptoms should be aware of their increased susceptibility to intestinal infection. The risk goes up the longer these types of medications are taken.

Avoiding C. Difficile Infection

The consequences of C. difficile infection can be serious with symptoms lasting weeks to months without proper treatment. Besides diarrhea, it can also cause fever, abdominal pain, dehydration, and electrolyte imbalances. In some cases, surgery may be needed to remove infected parts of the colon.

Thankfully, there are some things you can do to avoid C. diff and other opportunistic infections when taking acid-lowering medications like Benadryl for IBS relief:

• Take probiotics to support gut health and crowd out overgrowth of bad bacteria like C. diff.
• Maintain good hygiene and thoroughly wash hands after using the bathroom to prevent transmission.
• Stay well hydrated to counter fluid losses from infection-related diarrhea.
• Limit unnecessary antibiotic use which disturbs normal gut bacteria.
• See a doctor if experiencing 3 or more watery stools per day persisting longer than 2 days.

The Bottom Line - Is Benadryl Good for Helping IBS?

Benadryl may help provide relief for some IBS sufferers, especially those struggling with predominant diarrhea. By slowing gut motility and absorbed excess fluid in the colon, it can reduce loose bowel movements.

The antihistamine diphenhydramine also has antispasmodic effects on intestinal muscles that may ease painful cramps and abdominal contractions characteristic of IBS. And its soothing antihistaminic effects can curb underlying anxiety and help improve sleep quality.

However, Benadryl is not meant to be used as a long-term treatment solution. The ongoing anticholinergic action can cause uncomfortable side effects and also leaves users vulnerable to infection as it lowers protective stomach acid.

Individuals with IBS still wishing to use Benadryl for symptom relief should limit use to once daily before bedtime when needed. This will help manage side effects and reduce dependence while still harnessing benefits. Probiotics should also be taken regularly, and any alarming diarrhea should prompt seeing a doctor for evaluation.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional before starting any new treatment regimen.