# Anal fistula - Category: chronic - Review status: reviewed (every claim checked against a document named on this page) - Sources: Anorectal Fistula - StatPearls - NCBI Bookshelf - https://www.ncbi.nlm.nih.gov/books/NBK560657/ · ICPC-3 (WONCA International Classification of Primary Care, 3rd edition) class DD80.01 - condition scope only, no dose · No dose - referral pathway, no medicine given in primary care · Remsima 100 mg powder for concentrate for solution for infusion (infliximab) SmPC sections 4.1, 4.2, 4.3 and 4.4 (eMC product 3709) · Anal fistula - disease-level clinical article (anal-fistula-clinical.txt) - Verified date: 2026-08 ## Verified against - No dose - referral pathway, no medicine given in primary care - Remsima 100 mg powder for concentrate for solution for infusion (infliximab) SmPC sections 4.1, 4.2, 4.3 and 4.4 (eMC product 3709) - Anal fistula - disease-level clinical article (anal-fistula-clinical.txt) ## Treatment metadata - No drug therapy in primary care (Referral & Advice) - Infliximab — injection ## Complete treatment card ```text ANAL FISTULA Sources: Anorectal Fistula - StatPearls - NCBI Bookshelf - https://www.ncbi.nlm.nih.gov/books/NBK560657/ · ICPC-3 (WONCA International Classification of Primary Care, 3rd edition) class DD80.01 - condition scope only, no dose · No dose - referral pathway, no medicine given in primary care · Remsima 100 mg powder for concentrate for solution for infusion (infliximab) SmPC sections 4.1, 4.2, 4.3 and 4.4 (eMC product 3709) · Anal fistula - disease-level clinical article (anal-fistula-clinical.txt) Review status: REVIEWED against 3 sources listed above (2026-08) IS IT THIS? - reference only, to read alongside your own examination SYMPTOMS - what the patient reports (5) - Typical complaints include pain around the anus, drainage, itching, and skin irritation [anal pain · itching] - Rectal bleeding with bowel movements, changed bowel habits, mucus discharge, tenesmus, or weight loss are red flags not typical of a simple cryptoglandular fistula and need further workup [rectal bleeding · tenesmus · weight loss] - A prior history of perianal abscess, including how it was treated and whether it recurred, is relevant [abscess] - Chronic cough, weight loss, or a past tuberculosis history from an endemic area with a complex fistula raises suspicion for a tuberculous fistula [cough · fistula · weight loss] - A rash or high-risk sexual activity should raise suspicion for a sexually transmitted cause [rash] SIGNS - what you find (5) - Advanced malignant fistulas often show wasting, anemia, and malnutrition [anaemia · fistula · muscle wasting] - Mouth ulcers, skin nodules, erythema nodosum, or pyoderma gangrenosum point to a Crohn-related fistula [fistula · mouth ulcers · redness] - Tuberculous fistulas can come with enlarged lymph nodes, skin sinuses, and scrofuloderma [fistula · lymphadenopathy] - On rectal exam the internal opening feels like a firm, indurated spot, usually along the dentate line - An intersphincteric abscess feels like a boggy, tender swelling on rectal exam [abscess] TESTS (8) - The Goodsall rule predicts the internal opening's location from where the external opening sits, correct up to about 75 percent of the time - Low hemoglobin on bloodwork can point to anemia from inflammatory bowel disease or an underlying cancer - A raised white count and CRP can signal infection, a hidden abscess, or active Crohn disease - Endoscopic ultrasound performs about as well as MRI for mapping the tract and finding abscesses, and is quicker and cheaper - MRI is the gold-standard imaging test, correctly identifying the internal opening and tract in up to 100 percent of cases - Routine CT is not recommended for fistula evaluation because it is inaccurate compared with MRI and EUS - Colonoscopy is used when Crohn disease, cancer, or tuberculosis is suspected to check the rest of the colon - Anorectal manometry measures resting and squeeze pressures to assess sphincter function before surgery IF NOT THIS - what else fits (7) - An anal fissure causes painful defecation with drops of fresh blood, no external opening, and marked sphincter spasm on rectal exam - Thrombosed hemorrhoids cause perianal pain with a non-reducible swelling, often with a history of painless bleeding at the end of a bowel movement - Solitary rectal ulcer syndrome causes perianal pain, constipation, a sense of incomplete emptying, and bleeding, with an indurated anterior rectal wall on exam - A perianal abscess causes severe pain, swelling, warmth, and induration, usually without a visible external opening - Anal cancer presents as an ulcerated, proliferative growth at the anal opening with pain, bleeding, discharge, and incontinence - Sexually transmitted infections can cause anorectal pain, tenesmus, itching, perianal blisters or lesions, and swollen groin nodes - Perianal Crohn disease without an actual fistula can still cause abscesses, fissures, ulcers, and anorectal tumors Source StatPearls "Anorectal Fistula" - disease-level clinical article Status traced to the source above Rx: Main treatment | Anti-TNF biologic for perianal fistulising Crohn's disease - hospital- initiated MAIN TREATMENT 1. NO DRUG THERAPY IN PRIMARY CARE (REFERRAL & ADVICE) [1st line] Adult Abnormal tract between the anal canal and perianal skin, usually following an anorectal abscess. Needs surgical referral (fistulotomy or seton); GP gives analgesia, sitz-bath and hygiene advice, and antibiotics if there is active infection while awaiting surgery. - Refer, with advice Peds Children follow the same pathway: recognise and refer. No primary-care medicine is implied. Source No dose - referral pathway, no medicine given in primary care Why Abnormal tract between the anal canal and perianal skin, usually following an anorectal abscess. Needs surgical referral (fistulotomy or seton); GP gives analgesia, sitz-bath and hygiene advice, and antibiotics if there is active infection while awaiting surgery. Caution No medicine is prescribed for this in primary care - this entry is for recognition and referral. Anything given is decided by the service it is referred to. RED FLAG - Fever or spreading cellulitis (an active abscess), multiple or recurrent fistulas (consider Crohn's disease), or faecal incontinence: assess urgently and refer. ANTI-TNF BIOLOGIC FOR PERIANAL FISTULISING CROHN'S DISEASE - HOSPITAL-INITIATED 2. INFLIXIMAB [2nd line] Adult Intravenous infusion, dosed by body weight, with a three-dose induction. SmPC verbatim, for fistulising, active Crohn's disease: "5 mg/kg given as an intravenous infusion followed by additional 5 mg/kg infusions at 2 and 6 weeks after the first infusion." Maintenance verbatim: "Additional infusions of 5 mg/kg every 8 weeks". - Stopped after three doses if nothing has changed. SmPC verbatim: "If a patient does not respond after 3 doses, no additional treatment with infliximab should be given." Peds Age restriction: minimum 72 months (The paediatric licence is Crohn's disease from 6 years, not fistulising disease specifically. SmPC verbatim: "Remsima is indicated for treatment of severe, active Crohn's disease in children and adolescents aged 6 to 17 years, who have not responded to conventional therapy", at "5 mg/kg given as an intravenous infusion followed by additional 5 mg/kg infusion doses at 2 and 6 weeks after the first infusion, then every 8 weeks thereafter." A child with a perianal fistula belongs with paediatric gastroenterology and surgery together.) Source Remsima 100 mg powder for concentrate for solution for infusion (infliximab) SmPC sections 4.1, 4.2, 4.3 and 4.4 (eMC product 3709) Why Two claims, both from documents that were opened, and the boundary between them matters. The disease article names the drug and rules out the obvious alternatives, verbatim: "Aminosalicylates and corticosteroids, which are commonly used first-line agents for intestinal Crohn disease, are ineffective for perianal fistulizing disease. Biological agents such as anti-tumor necrosis factor alpha drugs (infliximab) and monoclonal antibodies like adalimumab and ustekinumab remain the cornerstone of medical management." The SmPC's indication section names the same disease, verbatim: "treatment of fistulising, active Crohn's disease, in adult patients who have not responded despite a full and adequate course of therapy with conventional treatment (including antibiotics, drainage and immunosuppressive therapy)." The dose belongs to Crohn's-related perianal fistula only. A cryptoglandular fistula with no inflammatory bowel disease behind it is a surgical problem, and the article is explicit that "The management of anorectal fistula is almost always surgical". Egypt registers one infliximab product, REMICADE 100 mg powder for intravenous infusion at roughly 5,900 EGP a vial, and a course is several vials per infusion at adult body weights. Caution RED FLAG - tuberculosis is excluded before the first infusion, not after it. SmPC verbatim: "Before starting treatment with infliximab, all patients must be evaluated for both active and inactive ('latent') tuberculosis." and "Appropriate screening tests, (e.g. tuberculin skin test, chest X-ray, and/or Interferon Gamma Release Assay), should be performed in all patients". The SmPC also warns that "in the majority of these reports tuberculosis was extrapulmonary". Latent tuberculosis is common in Egypt, so this is a real gate rather than a formality. Infection risk runs for months after the last infusion. SmPC verbatim: "Patients must be monitored closely for infections including tuberculosis before, during and after treatment with infliximab. Because the elimination of infliximab may take up to six months, monitoring should be continued throughout this period. Further treatment with infliximab must not be given if a patient develops a serious infection or sepsis." A blunted fever is part of the hazard - "suppression of TNF may mask symptoms of infection such as fever". Contraindicated outright in some patients. SmPC verbatim: "Patients with tuberculosis or other severe infections such as sepsis, abscesses, and opportunistic infections" and "Patients with moderate or severe heart failure (NYHA class III/IV)". An intravenous hospital drug, not a prescription pad drug. SmPC verbatim: "Remsima infusions should be administered by qualified healthcare professionals trained to detect any infusion-related issues." and "Infliximab has been associated with acute infusion- related reactions, including anaphylactic shock, and delayed hypersensitivity reactions". Drain the abscess first. The disease article has biologics frequently paired with an antibiotic - ciprofloxacin and metronidazole are the ones it names - where an abscess is present at the same time. An undrained perianal abscess under a TNF blocker is the worst of both. Egypt REMICADE 100 MG PD. VIAL FOR I.V. INF. 10 ML JANSSEN CILAG > SOFICOPHARM 5936.00 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)