Can IVIG cause diarrhea? Understanding a Common Side Effect

October 9, 2025 •

5 min read

Reports from clinical studies indicate that diarrhea is a recognized and sometimes frequent adverse event associated with intravenous immunoglobulin (IVIG) therapy, with some studies citing an incidence as high as 28%. Patients should understand that IVIG can cause diarrhea, recognize potential risk factors, and know how to manage this common side effect effectively.

Quick Summary

Intravenous immunoglobulin treatment is known to potentially cause diarrhea. Its occurrence can be influenced by dosage, infusion rate, and individual patient factors. Effective management includes adjusting infusion speed, staying hydrated, modifying diet, and communicating with healthcare providers.

Key Points

Diarrhea is a recognized side effect of IVIG therapy: Incidence can be significant, with some studies reporting it in over a quarter of patients depending on the formulation.
Infusion rate is a primary factor: Faster infusion rates are more likely to cause systemic side effects, including gastrointestinal issues like diarrhea.
Product formulation matters: The stabilizers used in different IVIG products can affect side effect profiles, with sucrose-based formulations noted as a potential risk factor for osmotic diarrhea.
Hydration and diet are key management tools: Staying well-hydrated and avoiding fatty, spicy foods can help mitigate or prevent GI distress during an infusion.
SCIg may be an alternative: Switching from IVIG to subcutaneous immunoglobulin (SCIg) is a viable option for patients who experience frequent or severe systemic side effects, as SCIg typically causes fewer systemic reactions.
Know when to contact your doctor: Seek immediate medical attention for persistent diarrhea (more than a day), severe symptoms like fever or dehydration, or any signs of bleeding.

What is IVIG and Why is it Prescribed?

Intravenous immunoglobulin (IVIG) is a therapeutic product derived from the pooled plasma of thousands of healthy donors. It is composed primarily of immunoglobulin G (IgG), a type of antibody crucial for the immune system's function. IVIG therapy is used to treat a wide range of conditions involving immune system dysfunction, including primary immunodeficiency diseases, autoimmune disorders, and various neurological conditions. By providing a high dose of healthy antibodies, IVIG can help bolster a weakened immune system or modulate an overactive one. While it is an essential treatment for many patients, it is not without potential side effects, including gastrointestinal issues like diarrhea.

The Link Between IVIG and Diarrhea

Diarrhea is one of the more commonly reported adverse events associated with IVIG therapy. While its incidence can vary depending on the specific IVIG product and patient population, it is important for patients and clinicians to be aware of the possibility.

Incidence and Severity

The frequency and severity of diarrhea from IVIG can differ. Some studies have found a relatively high incidence, with one report noting diarrhea in 28% of patients. Other data categorize it as a common or less frequent gastrointestinal side effect. The severity can also range from mild and self-limiting to severe, requiring a change in treatment. In general, most adverse effects, including diarrhea, tend to be mild to moderate and transient.

Possible Mechanisms

The exact reason why IVIG can cause diarrhea is not fully understood, but several mechanisms have been proposed:

Infusion Rate: A rapid infusion rate can increase the likelihood of systemic side effects, including gastrointestinal distress. The body's rapid exposure to a large amount of protein may trigger a reaction.
Complement Activation: The formation of immunoglobulin aggregates can activate the complement system, a part of the immune system, which can lead to adverse effects.
Product Formulation: Different IVIG products from various manufacturers contain different stabilizers, such as sucrose, maltose, or glucose. These ingredients can sometimes cause osmotic-type diarrhea, where the intestinal tract is flooded with excess water.
Mucosal Inflammation: In some cases, IVIG may induce inflammation in the intestinal mucosa, leading to chronic diarrhea. This mechanism is complex and still being researched.
Individual Patient Factors: A patient's underlying health status and sensitivities can influence their susceptibility to side effects. For example, individuals with pre-existing gastrointestinal conditions may be more vulnerable.

Risk Factors for IVIG-Related Diarrhea

Certain factors may increase a patient's risk of experiencing diarrhea or other systemic reactions during IVIG therapy:

High Dose or Rapid Infusion: Patients receiving a high dose of IVIG or undergoing a rapid infusion are more likely to experience side effects, including flu-like symptoms and gastrointestinal issues.
First Infusion: Adverse reactions are often more frequent during the first few infusions as the body adjusts to the treatment.
Specific IVIG Preparations: As mentioned, different stabilizers used in formulations can contribute to side effects. Products containing sucrose, for example, have been linked to increased risk in susceptible patients.
Dehydration: Patients who are dehydrated before or during their infusion may be more prone to side effects like headache and gastrointestinal issues.
Underlying Conditions: Patients with pre-existing autoimmune problems or inflammatory bowel disease may have a higher risk of experiencing or exacerbating gastrointestinal side effects.

Management Strategies for Diarrhea Caused by IVIG

For most patients, IVIG-related diarrhea is manageable. Here are several strategies recommended by healthcare professionals:

Adequate Hydration: Maintaining vigorous oral hydration is crucial to prevent dehydration, especially if experiencing diarrhea.
Adjust Infusion Rate: The infusion rate can often be slowed down to minimize side effects. This is a common and effective mitigation strategy.
Dietary Modifications: Avoiding greasy, spicy, or fatty foods before and during the infusion course can help minimize gastrointestinal distress. For some, avoiding gluten or lactose if intolerant may also help.
Premedication: In some cases, premedication with antihistamines or anti-inflammatory drugs may be recommended to reduce the severity of adverse effects. For diarrhea, over-the-counter medications like loperamide may be suggested by your doctor for mild cases.
Product Change: If side effects are persistent or severe, switching to a different IVIG product with a different stabilizer or formulation may resolve the issue.
Switch to SCIg: For patients with severe or persistent systemic side effects, switching from IVIG to subcutaneous immunoglobulin (SCIg) is an effective alternative. SCIg often causes fewer systemic reactions.

IVIG vs. SCIg: A Comparison of Gastrointestinal Side Effects


Feature	IVIG (Intravenous Immunoglobulin)	SCIg (Subcutaneous Immunoglobulin)
Incidence of Diarrhea	Can be very common in some studies (up to 28%). Systemic side effects are more frequent with IVIG.	Generally causes fewer systemic side effects, including diarrhea, than IVIG.
Mechanism	Higher potential for complement activation and rapid changes in fluid balance or reaction to product stabilizers due to high, rapid delivery.	Slower, more gradual absorption into the bloodstream reduces the peak concentration and likelihood of systemic reactions.
Typical Infusion Reactions	Systemic reactions are more common, including headache, fatigue, chills, nausea, and fever.	Local injection site reactions (redness, swelling, pain) are more common but usually mild and decrease over time. Systemic reactions are rare.
Management of GI Issues	May require premedication, slowing the infusion, or changing the product.	Less likely to cause systemic GI side effects. Focus often on local site management.
Patient Comfort	Infusion occurs at a medical center or at home with a nurse; risk of systemic side effects can be higher.	Can be self-administered at home; generally associated with higher patient satisfaction and fewer systemic side effects.

When to Seek Medical Attention

While mild diarrhea is a manageable side effect, certain symptoms warrant prompt medical attention:

Persistent Diarrhea: Diarrhea that lasts for more than a day or worsens despite management strategies.
Signs of Dehydration: Decreased urination, dark-colored urine, excessive thirst, and lethargy are warning signs.
Severe Symptoms: Uncontrolled vomiting, severe abdominal pain or cramps, or severe nausea.
Bloody Stool: The presence of blood in the stool or black, tarry stools should be reported immediately.
Fever: A high fever (above 101°F or 38°C) accompanied by gastrointestinal symptoms.

Conclusion

In summary, IVIG therapy can indeed cause diarrhea, but it is often a mild and manageable adverse effect. The incidence can vary significantly among patients and different product formulations, with factors like infusion rate and dosage playing a key role. For those who experience persistent or severe issues, management options exist, including adjusting the infusion rate, altering diet, and considering a switch to an alternative product or subcutaneous therapy (SCIg). Open communication with your healthcare provider is crucial for effective symptom management. By understanding the causes and management strategies, patients can continue their necessary treatment while minimizing discomfort. For more detailed medical information on IVIG adverse effects, authoritative sources like the NCBI PMC offer comprehensive reviews (see).

Frequently Asked Questions

The incidence varies depending on the specific IVIG product and patient, but it is a relatively common adverse effect. Some studies have reported diarrhea in up to 28% of patients receiving certain IVIG formulations.

For most patients, mild diarrhea is transient and resolves shortly after the infusion is completed. However, in some cases, it can last for several days, especially if linked to slower-acting mechanisms or specific product types.

Yes, slowing down the infusion rate is a very effective strategy for minimizing many IVIG side effects, including diarrhea. This is often one of the first adjustments a healthcare provider will make.

Yes, different IVIG products use different stabilizers (e.g., sucrose, maltose). Some patients may find they tolerate certain formulations better than others. A change in product or switching to subcutaneous immunoglobulin (SCIg) can reduce side effects.

Patients should maintain good hydration, especially with water-based fluids, and consider avoiding fatty, greasy, or spicy foods before and during the infusion. Avoiding gluten or lactose may also help if you have a known sensitivity.

You should contact your doctor if you experience diarrhea lasting more than a day, show signs of dehydration, have a high fever, experience severe abdominal cramps or nausea, or notice any blood in your stool.

SCIg, or subcutaneous immunoglobulin, is administered under the skin and typically results in fewer systemic side effects, including less diarrhea, because it is absorbed more slowly. Local reactions at the injection site are more common with SCIg, but these are often mild.