Dollar General Corp. shares fell to a new two-year low on Thursday, after the discount retailer announced disappointing results for its fiscal first quarter and lowered its outlook for the full year.

The macroeconomic environment, especially for our core customers, has been more challenging that expected. We are confident Dollar General will be able to deliver strong growth over the next few years, despite near-term pressures which affected our first quarter results and are anticipated to impact full-year revenue and earnings per share,” said Chief…