The most common complication is a urinary infection due to the catheterisation of the bladder (often necessary during surgery).
The most serious complication is haemorrhaging (bleeding during the operation). This is very rare but may necessitate changing the operating method (for example the surgeon may have to opt for a laparotomy, in order to control the bleeding), or the patient may have- if necessary- to undergo a blood transfusion during the operation.
Other complications include injury to nearby organs such as the bladder, the urethras, or even (though extremely rare) the digestive tube or the large blood vessels.
Less serious complications include bruising around the scars, infection at the site of the scars, or a urinary infection some time after the operation.
Other complications, although indirect, are also possible (these are linked to post surgery bed rest in hospitals):
This is why, as a preventative measure, patients wear support tights. Anticoagulants are also regularly prescribed and monitored by the anaesthetist.