Former South Africa coach Jake White, who led the Springboks to win the 2007 World Cup, had emergency abdominal surgery on Sunday.
The Vodacom Bulls director of rugby felt unwell during the recent trip to Wales, where the Bulls beat the Dragons 29-14 in the United Rugby Championship.
White, 59, was rushed to hospital upon returning to Pretoria after complaining of "debilitating stomach cramps".
The club said in a statement that he will take a break until 8 February.
Chief executive Edgar Rathbone said: "It is never nice to see one of our own down, but we are extremely confident that Jake is receiving the best medical attention available, and our team of medical experts will provide him with all the necessary support he will need to make a full recovery."
The Bulls' next match is in the European Rugby Champions Cup against Exeter Chiefs on Saturday.