What if the sharehoder bought some supplies for the company on his personal credit card?  I have seen this and I made a journal entry on the company books, debiting supplies and crediting either loan payable - Shareholder or just crediting S Corp distributions (assuming there was a suffiicent balance in the general ledger account so not to go negative.)  If this was my account I would do siometing similar, but debiting vehicle expense.  The credit could be paid in captal but I normally credit the other accounts mentioned above.