Step 1: Start from the usual treatment plan.
Gastric lymphoma responds well to chemotherapy, radiotherapy, and, for the MALT type, H. pylori eradication. An operation is not the first step in a straightforward case.
Step 2: List the situations where surgery becomes necessary.
Surgery steps in for heavy bleeding that cannot be stopped medically, for a perforated stomach wall, for a blockage of the stomach outlet, and for a lump of tumor that survives a full course of chemotherapy.
Step 3: Compare the four options against that list.
Bleeding, perforation, and leftover disease after chemotherapy all appear directly on that list of surgical triggers. Pain by itself is not on the list, since it is usually settled with painkillers and by shrinking the tumor with chemotherapy or radiotherapy.
Step 4: Conclude.
The option that does not belong with the true surgical indications is intractable pain.
$\boxed{\text{Intractable pain}}$