This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Disorders of the Anal Canal, Subject name: Surgery
Following hemorrhoidectomy the most common complication is: 
Select and explain. 
A. Bleeding, B. Urinary retention, C. Infection, D. Fecal impaction
B: Urinary retention
Answer: B: Urinary retention 
Explanation: Ans: b (Urinary retention) Ref: Bailey, p. 1256Degrees of hemorrhoidectomy (Ref: Bailey 1256)Ist - Bleed only; no prolapseIInd - Prolapse, but can be reduced digitally and will remain reduced.IIIrd - Continously remain prolapsedTreatment: Injection therapy -Ist degreeIInd degreeBanding -IInd degree too large for injection treatmentPhoto coagulation -Ist degreeIInd degreeHemorrhoidectomy -IIIrd degreeIInd degree not curable with other methodsFibrosed hemorrhoidsIntero-extemal hemorrhoid when external is well defined.Now the complications of hemorrhoidectomy:Eady:PainUrinary retentionReactionary haemorrhageLate:2o haemorrhage-usually 7-8 post op dayAnal strictureAnal fissure, sub mucosal abscessBridge:An arterial pile is a hemangiomatous condition of superior rectal artery