What Causes Pain In The Right Ankle?

hi..my boyfriend(29 years old,6'1",230lbs) woke up a week ago with a bruise on his right side hip area. He swears he did not hit it. If you touch it, it feels like something is protruding. He said it usually is not painful. The swelling or protrusion has gotten bigger in size but not the bruise. its not red or hot to the touch. the only other problems he's had is diarrhea for three days. he does have a bad right ankle that he has had surgery on a few years ago and probably needs to have another one. he said he has had increased pain in his ankle and it has gone up to his knee this week. he has taken a lot of goody powders. any ideas?