Risk Factors for Delayed Bleeding and Its Impact on Long‐Term Efficacy After Endoscopic Sclerotherapy for Internal Haemorrhoids by Inverted Colonoscopy Without Transparent Caps

Background We investigated the incidence, timing, risk factors and prognosis of delayed haemorrhage after endoscopic injection sclerotherapy (EIS) with lauromacrogol for internal haemorrhoids (IHs) using an inverted colonoscope without transparent caps. Methods The clinical data of 252 patients undergoing EIS with lauromacrogol for IH using an inverted colonoscope without transparent caps were retrospectively analysed. Delayed haemorrhage was defined as bleeding occurring between 24 h and 1 month postoperatively. The incidence, timing and volume of delayed bleeding were recorded. Clinical risk factors were analysed, and patients were followed up for 2 years. Results Delayed bleeding occurred in 17.5% (44/252) of patients, with a median onset of 2 (1–17) days. Among them, 97.7% (43/44) experienced < 20‐mL bleeding within 9 days that resolved spontaneously; one patient developed 500‐mL bleeding on postoperative Day 17. Multivariate logistic regression analysis showed that albumin < 40 g/L (odds ratio [OR]: 5.093; p < 0.001), triglycerides > 1.7 mmol/L (OR: 3.814, p < 0.001), Wexner Constipation Score ≥ 15 (OR: 5.340, p < 0.001) and > 4 injection sites (OR: 4.425, p = 0.005) were independent risk factors. The case of 500‐mL bleeding may have resulted from an excessively deep injection and a high injection position. After 2 years, treatment effectiveness did not differ significantly between patients with and without delayed bleeding ( p = 0.622). Conclusions Delayed bleeding is a common complication after EIS with lauromacrogol for IHs using an inverted colonoscope without transparent caps. Most cases are small volume, early onset and self‐limiting. Delayed bleeding does not affect long‐term EIS efficacy. Risk factors include hypertriglyceridaemia, hypoproteinaemia, postoperative constipation and > 4 injection sites. As delayed massive bleeding may occur when injections are too deep or positioned too high, EIS should be performed cautiously. Adherence to guidelines, including the use of a transparent cap or forward‐view endoscopy, is recommended.