Sammyjane tweeted: "Cringing so much, this guy just sticks a pipe up on his ass on The Island with Bear Grylls. absolutely disgusting."
Samxahemed complained: "The Island with Bear Grylls has made me gag and feel sick at the same time."
UK network Channel 4 received a number of complaints about The Island's latest episode, which was aired at 9pm, but would not say how many or the nature of the complaints.
Media regulator Ofcom also recevied a complaint about "a fish being killed in an inhumane way".
Ofcom said it had yet to decide whether to open a formal investigation into last night's show as to whether it breached its broadcasting code.
The charge against the episode of being "inhumane" was also levelled on Twitter, with Emily Manning tweeting: "Bear Grylls is inhumane."
An earlier episode of The Island with Bear Grylls - which featured a cayman killed for food - prompted 93 complaints to Ofcom.
Despite the flurry of complaints, Ofcom opted not to investigate the episode as it "could be justified by contextual factors".
Channel 4 said it had received "very few" complaints about last night's show.
SURVIVAL EXPERTS AND STAGED SCENES: THE ISLAND'S CONTROVERSY
Last month TV adventurer Bear Grylls and Channel 4 found themselves embroiled in a fakery row over The Island after it emerged that several of the contestants were professionals used to thriving in extreme conditions - and some of the scenes had been staged.
In the opening episode, the dehydrated camp-mates were seen running out of time to find a source of fresh drinking water.
When they eventually located one, viewers were not told that the murky supply was in fact a rubber-lined pool put there by the production crew.
It has also transpired that two caimans - a species of crocodile - were let loose for the group to catch. This was not disclosed in the broadcast.
Four of the 13 men other men have experience of surviving extreme conditions and some have previously worked with Grylls.
Rupert Smith worked with him on Channel 4's Escape To The Legion and cameraman Dan Etheridge worked with Grylls on Man vs Wild.
Sound recordist Kiff McManus has 10years' experience working in hostile conditions, while Matt Bennett was part of the team behind Ross Kemp On Gangs.
Channel 4 said in a statement: "It clearly states in the programme voiceover that trained crew are part of the experiment, living under exactly the same conditions as the other men."
- The Daily Mail
