You have hashimotos thyroiditis
and taking treatment for this , Is it replacement of thyroid harmone or any other medicine also.
For this local problem You should avoid costipation,avoid sitting for long period, drink lot of water and fluid, take salad,fresh fruits which provide fibres in diet.Use less spicy and oily food specially fried one,
also avoid spicy pickles and processed food.
You can take mild laxatives and stool softner if required
some growth in that particular region could be a small pile or skin tag for this you must see a Surgeon after examination will find out what it is and not every thing requires surgery.
Best wish for early recovery