Klippel Trenaunay syndrome commonly manifests as lower limb hypertrophy where vascular malformation occurs. However, up to 20% of patients with Klippel Trenaunay syndrome can have gastrointestinal involvement. An 18-year-old man with known Klippel Trenaunay syndrome in the left lower extremity underwent 99mTc-labeled red blood cell imaging to determine the site of gastrointestinal bleeding. The images did not reveal the site of active bleeding. However, diffuse non-moving activity in the left abdomen and pelvis was noted, which corresponded to hypertrophied colon and related blood vessels, consistent with intestinal involvement of Klippel Trenaunay syndrome.