The pictures, shared with the slogan 'Get Your Belly Out', are fast becoming the latest no-makeup-selfie-style internet trend.
According to South Wales Evening Post ,the #GetYourBellyOut campaign was started by 26-year-old Victoria Marie from Swansea, who was diagnosed with ulcerative colitis five years ago.
Speaking to the paper, Victoria said: "Over the past three months the awareness campaign has exploded and become a global success.
"I personally am passionate, driven and inspired to continue working hard at raising awareness for both Crohn's disease and ulcerative colitis.
"At the age of 26 I feel I have been to hell and back with this illness and it breaks my heart to contemplate how young children cope with such a life-changing illness."