This study is designed to evaluate the most applicable endpoints for evaluation of the Biomerica InFoods® IBS product.

The objective of this Endpoint Determination Study is to address key elements regarding a proposed larger clinical study design:

1. Comparing different potential primary outcome measures
2. Demonstrating that an exclusionary diet as determined by elevated IgG levels using the Biomerica InFoods® IBS Test is associated with alleviation of IBS symptoms
3. Demonstrating the ability to mask the sham diet
4. Demonstrating the safety of the exclusionary diet

Subjects' diets will be based on the results of the Biomerica, InFoods® IBS Test.

Immunoglobulin G (IgG) levels above a certain threshold are considered a positive response against a specific food or foods. It is expected that severity of symptoms of IBS will decrease when foods that generate a positive immune response in the Biomerica InFoods® IBS test are eliminated from the diet of the IBS patient.

The Endpoint Determination Study format will be a double-blinded randomized controlled clinical study enrolling subjects at two trial sites within the United States and designed to evaluate the use of IgG antibody guided dietary restrictions, based on the Biomerica InFoods® IBS Test, in the management of patients diagnosed with Irritable Bowel Syndrome (IBS).

The 2 sites will enroll approximately equal numbers of subjects. The target for each site is a minimum of 30 subjects in each classification: IBS with diarrhea [IBS-D], IBS with constipation [IBS-C] and IBS mixed [IBS-M] for a minimum of 90 patients per site, 180 total subjects for this study.

Inclusion Criteria:

• 21 years old or older.
• Able to read and understand English.
• Willing and able to sign the informed consent.
• Have access to a computer and/or cell phone access for Electronic Data Capture (EDC)
• Meets Rome IV Diagnostic Criteria for IBS
• Willing to follow a food elimination die
• Well controlled diabetic patients; A1C <7.5 and stable medication (>3 months, NOT Metformin
• Score between ≥ 3 and <7.5 on the Abdominal Pain Intensity Assessment (IBS_API) based on a weekly average of worst daily (in past 24 hours) abdominal pain on a 0 to 10 point scale.
• Patients who are on stable (> 3 months) doses of medications or treatments for their IBS (e.g., probiotics, fiber, Viberzi, Linzess, Amitiza, Alosetron, Plecanatide, anticholinergics, antidepressants, Zofran bile acid sequestrants, or anti-diarrheals) will be allowed to continue their medications as long as no change in treatment is planned for the duration of the study and no dose adjustment is made during the duration of the study.
• A positive IgG antibody response for at least one food in the Biomerica InFoods® IBS panel

Exclusion Criteria:

• Unable to provide consent.
• Cannot use EDC system due to no cell phone and no computer access
• Does not qualify for a diagnosis of IBS by IV Diagnostic Criteria
• Diagnosed IBS, but an IBS-API score of <3.0 and >7.5
• Pregnant or breastfeeding
• Patients with diabetes currently on Metformin
• Patients who have used Rifaximin in the past 3 months
• Patients engaged in another type of diet therapy, i.e. FODMAP
• Patients which physicians are anticipating starting a new medication, change in dosage, diet or other treatment for IBS during the study
• Chronic pain from other conditions besides IBS
• Current or previous use of narcotic medications within past 3 months
• History of prior GI surgery except for cholecystectomy or appendectomy.
• History with any of the following:

Gastroparesis, Uncontrolled GERD, Anorexia/bulimia Celiac disease Crohn's disease, Ulcerative Colitis, Abdominal/gastro cancer(s), Malabsorption syndrome(s).

• History of any other relevant inter-current medical conditions that could interfere with their participation in the study or the objectives of the study
• History of psychosis, schizophrenia, mania, or major psychiatric illness needing hospitalization within the past 6 months

It is not yet known if there will be a plan to make IPD available.