 [ Symptoms ] still have a painful lump on shin bone a month after hitting it hit shin bone on metal stairs a month has gone by and i have a painful lump where the bruse was [ Disease ] it could be many different things allergic response to dryer sheets detergents perfumes in the toilet tissue poor wiping stool is very acidic and can burn the skin anal fissures yeast or bacterial infections etc obviously without a thorough medical history and an examination it would not be possible to narrow down the many causes if you want to get this problem solved see your medical provider