I Just Got Out Of The Hospital With Stomach Issues

I just got out of the hospital with stomach issues and getting sick for 3 years now. I noticed my third day out of the hospital there is a Huge dark purple and pink bruise on my lower right stomach, BUT it does not hurt to touch. i did notice slight discomfort (internally) last night but experience discomfort on a daily basis. The only surgery i had was my gallbladder about a year ago and I have had 3 endoscopes and 1 sigmoidoscopy where they removed a couple small polyps. I am 6 foot 2 and 300 pounds, me being sick has dropped my weight 45 pounds since March. However I have always been active in sports. I am young (20) and scared. Should i be worried about this?