# Small Intestinal Bacterial Overgrowth (SIBO) - Category: chronic - Review status: reviewed (every claim checked against a document named on this page) - Sources: ACG Clinical Guideline: Small Intestinal Bacterial Overgrowth 2020 · Egyptian National Drug Formulary - Antimicrobial 2023 (metronidazole monograph) · Small Intestinal Bacterial Overgrowth - StatPearls - NCBI Bookshelf (NBK546634) - the article states the dose for this indication · Cyanocobalamin DailyMed label, SetID 41ac0dc1-0a71-4c69-8e25-ba838f5f16a3, dosage and administration - Verified date: 2026-08 ## Verified against - ACG Clinical Guideline: Small Intestinal Bacterial Overgrowth 2020 - Egyptian National Drug Formulary - Antimicrobial 2023 (metronidazole monograph) ## Treatment metadata - Rifaximin — 550 mg — oral.solid - Metronidazole — 250 mg — oral.solid - Neomycin — 500 mg — oral.solid - Cyanocobalamin — injection ## Complete treatment card ```text SMALL INTESTINAL BACTERIAL OVERGROWTH (SIBO) Sources: ACG Clinical Guideline: Small Intestinal Bacterial Overgrowth 2020 · Egyptian National Drug Formulary - Antimicrobial 2023 (metronidazole monograph) · Small Intestinal Bacterial Overgrowth - StatPearls - NCBI Bookshelf (NBK546634) - the article states the dose for this indication · Cyanocobalamin DailyMed label, SetID 41ac0dc1-0a71-4c69-8e25-ba838f5f16a3, dosage and administration Review status: REVIEWED against 2 sources listed above (2026-08) IS IT THIS? - reference only, to read alongside your own examination SYMPTOMS - what the patient reports (5) - Bloating, flatulence, and watery diarrhea alongside vague abdominal discomfort are typical [abdominal distension · abdominal pain · diarrhoea · flatulence] - Fat malabsorption drives steatorrhea and weight loss, more so with altered gut anatomy [steatorrhoea · weight loss] - B12 deficiency from the condition can cause weakness, sensory ataxia, and paresthesia [tingling · unsteadiness] - Severe vitamin D deficiency can cause perioral numbness and hand or foot paresthesias from low calcium [numbness] - D-lactic acidosis can cause confusion, slurred speech, seizures, and unsteady gait in short bowel or bypass patients [confusion · seizures · slurred speech] SIGNS - what you find (2) - Exam findings are usually unremarkable outside of significant malnutrition - A splashing sound over the abdomen from fluid-filled bowel loops is an uncommon finding TESTS (7) - No single test is the accepted gold standard for diagnosing this condition - A carbohydrate breath test is positive with a hydrogen rise over 20 parts per million within 90 minutes, or a methane level above 10 parts per million - Jejunal aspirate culture supports the diagnosis when bacterial counts exceed 1000 CFU per mL - Glucose breath testing sensitivity ranges widely, from 20 to 93 percent, with specificity 45 to 86 percent - Lactose breath testing sensitivity and specificity are also wide-ranging, roughly 17 to 68 percent and 44 to 86 percent - Upper and lower endoscopy can rule out atrophic gastritis and Crohn disease as alternative causes - Magnetic enterography is more sensitive for detecting small bowel strictures but is costly IF NOT THIS - what else fits (3) - IBS presents with recurrent abdominal pain tied to bowel movements and altered stool frequency or appearance - Celiac disease is distinguished by positive celiac serologies together with a negative carbohydrate breath test - Crohn disease can show transmural inflammation, granulomas on biopsy, and perianal fissures or fistulas, unlike this condition Source StatPearls "Small Intestinal Bacterial Overgrowth" - disease-level clinical article Status traced to the source above Rx: Main treatment | Second antibiotic given with rifaximin for methane-predominant overgrowth | Replaces the B12 lost to malabsorption MAIN TREATMENT - choose one 1. RIFAXIMIN [1st line] Adult 550 mg 3 times daily (or 400 mg 3 times daily) x 14 days Peds Specialist pediatric gastroenterology use only Source ACG Clinical Guideline: Small Intestinal Bacterial Overgrowth 2020 Why Non-absorbable gastrointestinal-targeted antibiotic with minimal systemic side effects Caution Rifaximin is the first-line treatment for hydrogen-predominant SIBO per ACG 2020. Address underlying motility or structural cause to prevent high recurrence rate. Rifaximin is a non-absorbable antibiotic (<0.4% systemic absorption). Egypt IDIBACT 550 MG 20 F.C.TAB. INTERNATIONAL... 103.75 EGP (5.19/unit) ROLAXIMINE 550 MG 30 F.C. TAB. EVA PHARMA > ... 225.00 EGP (7.50/unit) RIFAXEROSE 550 MG 10 F.C. TABS. AVERROES PHARMA 82.00 EGP (8.20/unit) BIOREFAMIN 550 MG 10 F.C.TABS. P & C LABS > ... 148.00 EGP (14.80/unit) DUFAXIMIN 550 MG 28 F.C. TABS. AUG PHARMA 480.00 EGP (17.14/unit) FATROXIM 550 MG 30 F.C. TAB. EGPI > ATM PH... 516.00 EGP (17.20/unit) GASTROBIOTIC 550 MG 30 F.C. TAB. ANDALOUS PHARMA 516.00 EGP (17.20/unit) TRAVIGUARD 550 MG 20 F.C. TABS. P AND C LABS ... 344.00 EGP (17.20/unit) 2. METRONIDAZOLE [2nd line] Adult 250 mg 3 times daily x 10-14 days Peds 7.5 mg/kg/dose [child max 250 mg] (7.5 mg/kg 3 times daily for 10-14 days) 3kg -> 22.5 mg/dose 4kg -> 30 mg/dose 5kg -> 37.5 mg/dose 6kg -> 45 mg/dose 7kg -> 52.5 mg/dose 8kg -> 60 mg/dose 9kg -> 67.5 mg/dose 10kg -> 75 mg/dose 11kg -> 82.5 mg/dose 12kg -> 90 mg/dose 13kg -> 97.5 mg/dose 14kg -> 105 mg/dose 15kg -> 112.5 mg/dose 16kg -> 120 mg/dose 17kg -> 127.5 mg/dose 18kg -> 135 mg/dose 19kg -> 142.5 mg/dose 20kg -> 150 mg/dose 21kg -> 157.5 mg/dose 22kg -> 165 mg/dose 23kg -> 172.5 mg/dose 24kg -> 180 mg/dose 25kg -> 187.5 mg/dose 26kg -> 195 mg/dose 27kg -> 202.5 mg/dose 28kg -> 210 mg/dose 29kg -> 217.5 mg/dose 30kg -> 225 mg/dose 31kg -> 232.5 mg/dose 32kg -> 240 mg/dose 33kg -> 247.5 mg/dose 34kg -> 250 mg/dose (capped) 35kg -> 250 mg/dose (capped) 36kg -> 250 mg/dose (capped) 37kg -> 250 mg/dose (capped) 38kg -> 250 mg/dose (capped) 39kg -> 250 mg/dose (capped) 40kg -> 250 mg/dose (capped) 41kg -> 250 mg/dose (capped) 42kg -> 250 mg/dose (capped) 43kg -> 250 mg/dose (capped) 44kg -> 250 mg/dose (capped) 45kg -> 250 mg/dose (capped) 46kg -> 250 mg/dose (capped) 47kg -> 250 mg/dose (capped) 48kg -> 250 mg/dose (capped) 49kg -> 250 mg/dose (capped) 50kg -> 250 mg/dose (capped) Source Egyptian National Drug Formulary - Antimicrobial 2023 (metronidazole monograph) Why Alternative systemic antibiotic option for SIBO when rifaximin is unavailable or cost- prohibitive Caution Metronidazole is an alternative for SIBO; it has a higher rate of systemic side effects than rifaximin. Avoid alcohol completely during treatment. Egypt TRICHOGYL 250 MG 20 TAB. EL NASR 4.35 EGP (0.22/unit) FLAGICURE 250MG 20 TAB. KAHIRA 7.00 EGP (0.35/unit) TRICHOCID 250MG 20 TAB. CID 7.00 EGP (0.35/unit) METRONIDAZOLE-MUP 250 MG 20 F.C. TABS. MUP 11.00 EGP (0.55/unit) AMRIZOLE 250 MG 20 TABS. AMRIYA 20.00 EGP (1.00/unit) METROZOLE 250MG 20 TAB. MEMPHIS 20.00 EGP (1.00/unit) DUMOZOL 125MG/5ML SUSP. 125ML MINA PHARM > ... 5.75 EGP -> ? strength differs, ? different route - not oral solid METROZOLE 125MG/5ML SUSP. 120 ML MEMPHIS 19.50 EGP -> ? strength differs, ? different route - not oral solid SECOND ANTIBIOTIC GIVEN WITH RIFAXIMIN FOR METHANE-PREDOMINANT OVERGROWTH - give alongside 3. NEOMYCIN [add-on - not a substitute] Adult 1000 mg a day by mouth, alongside rifaximin x 2 weeks Peds No paediatric dose for this indication in the sources opened; the formulary's paediatric neomycin doses are for hepatic encephalopathy and bowel preparation. Source Small Intestinal Bacterial Overgrowth - StatPearls - NCBI Bookshelf (NBK546634) - the article states the dose for this indication Why The card treats every SIBO the same way. Methane-predominant overgrowth responds poorly to rifaximin alone, and the article gives a specific two-drug regimen for it. Caution It is an adjunct to rifaximin for the methane-predominant type, not a treatment on its own. Do not exceed two weeks; a little is absorbed and prolonged use risks deafness and kidney damage. Contraindicated in intestinal obstruction and in inflammatory or ulcerative bowel disease. Reduce or stop it if the kidney function falls, and avoid it in anyone who has reacted badly to another aminoglycoside. Egypt NEOMYCIN 500 MG 20 TAB. MEMPHIS 19.00 EGP (0.95/unit) REPLACES THE B12 LOST TO MALABSORPTION - give alongside 4. CYANOCOBALAMIN [add-on - not a substitute] Adult 100 mcg by intramuscular or deep subcutaneous injection daily for six or seven days; the label then lengthens the interval step by step before settling at 100 mcg monthly for life Peds No paediatric dose in the sources opened. Source Cyanocobalamin DailyMed label, SetID 41ac0dc1-0a71-4c69-8e25-ba838f5f16a3, dosage and administration - verbatim: "A dose of 100 mcg daily for six or seven days should be administered by intramuscular or deep subcutaneous injection." Why Low B12 with macrocytic anaemia is the classic laboratory picture of SIBO and it causes real neurological harm. Because the problem is malabsorption, the injection is the route that works. Caution Give it intramuscularly or deep subcutaneously, never intravenously - almost all of an intravenous dose is lost in the urine. Contraindicated in anyone sensitive to cobalt or to vitamin B12 itself. Confirm the deficiency before treating, and correct the overgrowth as well, or it will come straight back. Egypt CIDOLVEX 1MG/ML I.M AMP. CID 5.20 EGP BETO-12 1MG/ML 2 AMP. AMOUN 11.00 EGP RUBIVAMIN 1000 MCG 5 AMPS. MISR 42.50 EGP BETOLVEX 1MG/ML 2 AMPS. I.M. MINA PHARM 64.00 EGP BETOLVEX 1MG/ML 2 PRE-FILLED SYRINGE I.M. MINA PHARM 110.00 EGP Prices are indicative (dataset snapshot 2026-06); verify with the pharmacy. ``` --- Dawaa Reference is a reference for prescribers, not a medical device, and does not replace clinical judgement. [Privacy policy](/privacy)