Andrew Lane, 61, contracted necrotising fasciitis - a potentially fatal infection - following an operation to remove his prostate gland.
He was left fighting for his life at Southend Hospital, Essex, but managed to pull through and survive.
However, his genitals were so badly damaged that he lost most of his p3nis and is now no longer able to have s3x.
So much diseased tissue had to be removed that it also left him with a protruding stomach, where the outer tissue had been 'eaten' away.
He was forced to use a catheter and colostomy bag for two years and has had to have a special device fitted to help him urinate.
Mr Lane, from Thurrock, spent eight weeks in hospital following the incident in March 2013 and said he has only recently started to come to terms with his injuries.
He is now taking legal action against Southend University Hospital NHS Foundation Trust over claims that his bowel was punctured during the original operation.
But this was not detected for days afterwards, which led to the infection.