After laparotomy hyperophied muscle is cut along the whole length adequately until mucosa bulges out, then pyloromyotomy is done. in Heller&;s operation muscle of the cardiac are cut to allow passage of food ,and is done in achalasia cardia Truncal vagotomyis done by denervating the main branch which is supply in pylorus as in cases like peptic ulcerarltion Delorme&;s operation is done for repairing a external rectal prolapse Reference: SRB 5th edition page no. 821 & internet