I've been itchy for over a week in armpit kept scratching now i have a bump under the skin.. not painful also have possible ibs use colpermin?

A few thoughts: Colpermin usually doesn't cause itching but because it's a natural substance, it's hard to say for sure because those compounds are not as regulated as prescription medications. You could try not taking it for a few daysto see if it helps your symptoms. Try not to scratch as this can cause irritation to your skin. Possibly the bump under the skin is a cyst that formed as a result of the scratching