12-phase flow (12)

1. 1FRAME
   Establish scope — chronic haemorrhoidal disease vs an acute subacute episode (thrombosed external haemorrhoid / acute anal fissure / significant bleeding / perianal abscess pointer); adult vs pregnancy/postpartum; the painless-internal-bleeding vs painful-thrombosed-external/fissure pivot (ASCRS 2024/2023)
   inputs: acute_perianal_pain
   advance: condition (haemorrhoid / fissure / thrombosed external / abscess), acuity and population framed
2. 2ENTRY
   Recognise the presenting trigger — bright-red rectal bleeding (NOT assumed haemorrhoidal), prolapse/perianal lump, acute severe perianal pain, pruritus/discharge, known-disease review, or iron-deficiency anaemia with anorectal symptoms (ASCRS 2024; Siminoff 2015 PMID 26504796)
   inputs: rectal_bleeding
   advance: one entry trigger present
3. 3CONTEXT
   Age (CRC pre-test probability), sex, bowel habit/constipation/straining, pregnancy/postpartum status, anticoagulant/antiplatelet therapy, immunosuppression/HIV, IBD history, prior anorectal surgery/continence, family history CRC/IBD (ASCRS 2024/2023)
   inputs: age, sex, bowel_habit_constipation_straining, pregnancy_status, anticoagulant_antiplatelet, immunocompromise_hiv
   actions: panel.cmp
   advance: demographics + bowel habit + pregnancy + anticoagulation + comorbidity captured
4. 4RED_FLAGS
   RECTAL BLEEDING IS NOT ASSUMED HAEMORRHOIDAL — alarm features (age ≥45 / per current screening, change in bowel habit, weight loss, iron-deficiency anaemia, family history CRC/IBD, bleeding atypical for haemorrhoids, incomplete prior screening, persistent/atypical bleeding) mandate colorectal-source exclusion; perianal abscess / Fournier gangrene (immunocompromised/diabetic — perianal sepsis) is a surgical emergency; brisk bleeding / haemodynamic compromise → gi.lgib.core.v1. Haemorrhoid attribution of rectal bleeding is the most common missed CRC diagnostic opportunity (Siminoff 2015 PMID 26504796; ASCRS 2024)
   inputs: alarm_features, age, rectal_bleeding
   actions: workup.lgib, workup.colorectal_screening, workup.colonoscopy_diagnostic, workup.acute_abdomen
   advance: no alarm feature and no perianal sepsis, OR colorectal-source workup / surgical-emergency route activated
5. 5INITIAL_WORKUP
   Perianal inspection + digital rectal exam + anoscopy/proctoscopy (the diagnostic standard for internal haemorrhoids/fissure); CBC for anaemia from chronic bleeding; iron studies if iron-deficiency pattern; INR/coagulation if anticoagulated. The load-bearing branch: any alarm / screening gap / iron-deficiency anaemia → colorectal-source workup (colonoscopy) BEFORE benign attribution (ASCRS 2024; Siminoff 2015 PMID 26504796)
   inputs: cbc, ferritin_iron_studies, inr_coagulation
   actions: panel.cbc, panel.iron, panel.coag, workup.lgib, workup.colonoscopy_diagnostic, cascade.labs_command
   advance: anoscopy/DRE done, anaemia/coag assessed, and colorectal source excluded or routed
6. 6BRANCHING_WORKUP
   Classify external vs internal vs mixed; assign Goligher grade I (no prolapse) / II (prolapse, spontaneous reduction) / III (prolapse, manual reduction) / IV (irreducible); fork thrombosed-external (duration for 72-h window) vs acute anal fissure (posterior-midline typical) vs perianal abscess. LATERAL / multiple / painless / non-healing fissure → secondary-cause workup (Crohn, malignancy, TB, syphilis, HIV) and route to gi.crohns.core.v1; anaemia → iron-deficiency + mandatory colonoscopy (ASCRS 2024/2023)
   inputs: anorectal_prolapse, ibd_history
   actions: workup.colonoscopy_diagnostic, workup.lgib
   advance: grade + external/internal/mixed + thrombosis/fissure/abscess phenotype + secondary-cause status assigned
7. 7DIFFERENTIAL
   Haemorrhoids vs colorectal/anal carcinoma (THE pivotal miss — Siminoff 2015 PMID 26504796), anorectal varices in portal hypertension (NOT haemorrhoids — do NOT band/inject), anal fissure (idiopathic vs secondary), perianal abscess/fistula, rectal prolapse, condylomata acuminata, pruritus ani, proctitis/IBD, solitary rectal ulcer syndrome (ASCRS 2024/2023)
   inputs: portal_hypertension_cirrhosis
   advance: benign anorectal diagnosis confirmed AND colorectal/anal malignancy + anorectal varices excluded or routed
8. 8RISK_STRATIFICATION
   Goligher grade + symptom burden + bleeding-related anaemia severity + thrombosis acuity (<72 h excision window) + periprocedural bleeding risk (HAS-BLED if anticoagulated) + host-risk modifiers (pregnancy, IBD, immunocompromise, portal HTN, baseline continence pre-sphincterotomy) (ASCRS 2024/2023)
   inputs: anorectal_prolapse, continence_prior_anorectal_surgery, anticoagulant_antiplatelet
   actions: calc.has_bled
   advance: grade + anaemia severity + thrombosis window + periprocedural bleeding risk + continence risk documented
9. 9TREATMENT
   CONSERVATIVE for all + grade I–II: bulk fibre (psyllium/methylcellulose — roughly halves persistent symptoms/bleeding, RR ~0.50; Alonso-Coello PMID 16235372/16405552), fluids, bowel-habit modification, sitz baths, short-course duration-limited topical analgesic/steroid (skin-atrophy limit), ± MPFF/diosmin flavonoid (bleeding/pruritus benefit, NOT pain; Perera PMID 22895941). OFFICE PROCEDURES grade I–III refractory: rubber-band ligation (most effective non-surgical — excisional better remission RR 1.68 [1.00–2.83] but more morbidity, Shanmugam PMID 16034963), sclerotherapy, infrared coagulation. SURGERY grade III–IV/refractory/mixed/thrombosed: excisional haemorrhoidectomy (most effective, most pain), stapled haemorrhoidopexy (less early pain, inferior long-term — eTHoS PMID 27726951), HAL-Doppler (vs RBL — HubBLe PMID 27236344). Thrombosed external <72 h → excision (resolution 3.9 vs 24 d, recurrence 6.3% vs 25.4%; Greenspon PMID 15486746). Anal-fissure ladder: fibre + sitz → topical CCB (diltiazem/nifedipine) or GTN (first-line medical; GTN headache 20–30%) → botulinum toxin → lateral internal sphincterotomy (most effective, incontinence risk; Nelson PMID 22336789). Periprocedural anticoagulation hold/bridge plan. Pregnancy: conservative first-line, drug-safety tiers, defer surgery (ASCRS 2024/2023)
   inputs: bowel_habit_constipation_straining, pregnancy_status, anticoagulant_antiplatelet, creatinine
   advance: grade/phenotype-appropriate plan executed (conservative / office procedure / surgery / fissure ladder step) with periprocedural anticoagulation managed
10. 10DISPOSITION
    Primary-care conservative management for most chronic haemorrhoidal disease and acute anal fissure; colorectal referral (transition) for office procedure, surgery, refractory disease, or grade III–IV; ED for acutely thrombosed external haemorrhoid with severe pain within the 72-h excision window, significant/symptomatic bleeding, or perianal sepsis/Fournier gangrene (ASCRS 2024/2023)
    inputs: acute_perianal_pain, alarm_features
    advance: destination set (primary-care / colorectal referral / ED) and colorectal-source exclusion status documented
11. 11MONITORING
    Symptom/bleeding response at 4–8 weeks; anal-fissure healing on topical therapy (re-evaluate at 6–8 wk; non-healing → escalate ladder / secondary-cause workup); ENFORCE topical-steroid duration limit (≤7–14 days — skin atrophy); GTN headache/hypotension/PDE5i-interaction monitoring; post-procedure bleeding/pain/urinary retention; continence after sphincterotomy; anaemia trend on iron repletion; re-screen emergent alarm features → re-enter RED_FLAGS colorectal workup (ASCRS 2024/2023; Nelson PMID 22336789)
    inputs: cbc, creatinine, continence_prior_anorectal_surgery
    actions: panel.cbc, panel.iron
    advance: treatment response assessed, fissure healing tracked, drug-duration and continence/bleeding safety documented
12. 12FOLLOWUP
    Recurrence counselling + sustained bowel-habit/fibre maintenance; CONFIRM age-appropriate colorectal cancer screening is completed/up to date (the safety close-out — never close a rectal-bleeding episode without it); pregnancy postpartum resolution counselling (most resolve); escalate non-responders to colorectal referral; route IBD (gi.crohns.core.v1), portal-HTN/varices (gi.cirrhosis.core.v1), or malignancy as identified (ASCRS 2024/2023)
    inputs: age, pregnancy_status, bowel_habit_constipation_straining
    actions: workup.colorectal_screening
    advance: recurrence/bowel-habit counselling delivered, CRC screening confirmed up to date, follow-up scheduled, onward routing done