First, the IgE test, without exposure, can slowly become negative. And a positive in 0.1 not higher on typical labs.
IBS in my opinion, should always have this ruled-out. (Along with Mast Cell Excessive Reactivity).
Alpha-gal syndrome (AGS) is a serious, potentially life-threatening allergic condition triggered by consuming meat from mammals (such as beef, pork, lamb, venison, or rabbit) or products containing alpha-gal, a sugar molecule found in most mammalian cells. In the United States, this condition is most commonly associated with bites from the lone star tick. (cdc.gov).
This allergic sugar can be made by ticks and does not require mammal contact.
Unlike many food allergies that occur immediately after exposure, symptoms of Alpha-gal syndrome typically appear several hours after consuming the offending substance. (mayoclinic.org)
Common Signs and Symptoms
The symptoms of Alpha-gal syndrome can vary significantly from person to person, ranging from mild to severe, and may involve multiple organ systems:
Skin Reactions
Hives (urticaria).
Itching, or itchy scaly skin (eczema).
Swelling of the lips, face, tongue, and throat (angioedema).
Gastrointestinal Distress
Severe stomach pain.
Nausea and vomiting.
Heartburn or acid reflux.
Diarrhea.
Respiratory Symptoms
Wheezing or difficulty breathing.
Shortness of breath.
Cardiovascular and Systemic Symptoms
Drop in blood pressure.
Dizziness or feeling faint.
Anaphylaxis, which is a severe, life-threatening allergic reaction that requires immediate emergency medical attention. (cdc.gov)
Key Characteristics
Delayed Reaction
The hallmark of Alpha-gal syndrome is the delayed onset of symptoms. While most food allergies cause reactions within minutes, (mayo) individuals with AGS may not experience symptoms until 3 to 12 hours after eating mammalian products.
You may wake up in the middle of the night hours after eating. And this delay can cause it to be missed many years.
Variability
Not every person with AGS will experience every symptom, and the severity of a reaction can fluctuate depending on the quantity of food consumed and the presence of other factors, such as exercise or alcohol consumption, which may exacerbate the reaction in some individuals. (mayoclinic.org)