Rifaximin for IBS without Constipation: TARGET 3
New England Journal of Medicine (2011)
Significantly improved IBS symptoms including bloating, abdominal pain, and stool consistency vs placebo over 2 weeks, with durable response.
Rifaximin
Oral tablet (275mg)Not available in all statesMarketing purposes only. Actual medications, if prescribed, are dispensed by a licensed pharmacy.
gut
RifaximinRifaximin
Non-absorbable rifamycin antibiotic acting locally in the GI tract. FDA-approved for traveler's diarrhea, hepatic encephalopathy, and IBS-D. Key role in SIBO treatment protocols due to gut-limited activity with minimal systemic absorption.
Gut-limited action with minimal systemic absorption
Effective for SIBO eradication
Does not significantly disrupt colonic microbiome at standard doses
Low resistance development
No commitment · HSA/FSA eligibleNo commitment · HSA/FSA eligible
How it works
Mechanism of action
Inhibits bacterial RNA polymerase, with broad-spectrum activity against gram-positive and gram-negative aerobes and anaerobes. <0.4% systemic absorption ensures gut-localized action with minimal systemic side effects or resistance concerns.
The baseline panel.
Every Marek client receives this baseline panel before a provider review. Your provider may add additional biomarkers based on your health history, symptoms, and goals, pulling from 1,000+ available markers. See more biomarkers →
Hormone Profile
12 markers
Sex hormones
- Total TestosteroneLC/MS
- Free TestosteroneEquilibrium Dialysis
- Estradiol, Sensitive / UltrasensitiveLC/MS
- Sex Hormone Binding Globulin (SHBG)
- ProgesteroneLC/MSFemale panel
- Prolactin
- Luteinizing Hormone (LH)
- Follicle-Stimulating Hormone (FSH)
- hCG, Total, QuantitativeFemale panel, pre-menopause
Adrenals & neurosteroids
- Cortisol
- DHEA-S
Growth hormone / IGF-1
- Insulin-Like Growth Factor I (IGF-1)
Thyroid Status
3 markers
Thyroid hormones
- Thyroid Stimulating Hormone (TSH)
- Free T4
- Free T3
Heart Health
9 markers
Cardiovascular health
- Total Cholesterol
- HDL Cholesterol
- LDL Cholesterol
- LDL:HDL Ratio
- VLDL Cholesterol
- Triglycerides
- Apolipoprotein-B (ApoB)
- C-Reactive Protein, High Sensitivity (hsCRP)
- Lipoprotein(a) (Lp(a))
Metabolism
3 markers
Insulin sensitivity
- Blood Glucose
- Fasting Insulin
- HbA1c
Organ Function
26 markers
Liver & pancreas
- AST
- ALT
- Bilirubin, Total
- γ-Glutamyl Transferase (GGT)
Kidney function
- BUN
- Creatinine w/ eGFR
Comprehensive Metabolic Panel (CMP)
- Glucose
- Blood Urea Nitrogen (BUN)
- Creatinine
- eGFR
- BUN/Creatinine Ratio
- Sodium
- Potassium
- Chloride
- Carbon Dioxide, Total
- Calcium
- Protein, Total
- Albumin
- Globulin, Total
- Albumin/Globulin (A/G) Ratio
- Alkaline Phosphatase (ALP)
- AST
- ALT
Prostate health
- Prostate-Specific Antigen (PSA)Male panel
- Free PSAMale panel
- % Free PSAMale panel
Nutrient Status
31 markers
Vitamins & minerals
- Vitamin D, 25-OHD (25-Hydroxy)
- Magnesium, RBC
Iron status
- Iron
- Iron Saturation
- TIBC
- UIBC
- Ferritin
Complete Blood Count (CBC)
- White Blood Count (WBC)
- Red Blood Count (RBC)
- Hemoglobin (Hgb)
- Hematocrit (HCT)
- MCV
- MCH
- MCHC
- Red Cell Distribution Width (RDW)
- Platelets
- Neutrophils
- Neutrophils (Absolute)
- Lymphocytes
- Lymphocytes (Absolute)
- Neutrophil/Lymphocyte Ratio
- Monocytes
- Monocytes (Absolute)
- Eosinophils
- Eosinophils (Absolute)
- Basophils
- Basophils (Absolute)
- Immature Cells
- Immature Granulocytes
- Immature Granulocytes (Absolute)
- NRBC, w/ Reflex for Immature Cells
Clinical evidence
The research behind Rifaximin.
Safety profile
Monitoring & safety information.
Commonly reported side effects
- Nausea
- Flatulence
- Headache
- Abdominal pain
Less common but serious risks
- C. difficile infection (rare)
- Hypersensitivity reactions
Generally not appropriate for
- Hypersensitivity to rifaximin or rifamycin class
- Intestinal obstruction
Typical monitoring
- Symptom resolution
- SIBO breath test (post-treatment)
- Liver function (hepatic encephalopathy indication)
FAQ
Quick answers.
Non-absorbable rifamycin antibiotic acting locally in the GI tract. FDA-approved for traveler's diarrhea, hepatic encephalopathy, and IBS-D. Key role in SIBO treatment protocols due to gut-limited activity with minimal systemic absorption.
Gut-limited action with minimal systemic absorption. Effective for SIBO eradication. Does not significantly disrupt colonic microbiome at standard doses. Low resistance development.
Common side effects include: nausea, flatulence, headache, abdominal pain. Most side effects are dose-dependent and may resolve with continued use or dose adjustment.
Non-absorbable rifamycin antibiotic acting locally in the GI tract. FDA-approved for traveler's diarrhea, hepatic encephalopathy, and IBS-D. Key role in SIBO treatment protocols due to gut-limited activity with minimal systemic absorption.
Treatments are dependent on licensed clinical prescription. Client costs vary based on individual labs and panel in treatments and services.