It seems that it is as long as you don’t consume more than 2 cups a day.
From the SCD Knowledge Base:
Originally Elaine wrote: Green tea has been associated in some studies with the onset of ulcerative colitis and is not allowed on SCD™. This may seem odd as the popular wisdom currently is that it has anti-inflammatory properties, but there are many things on SCD™ that are ’supposed’ to be good for IBD, but which we avoid. Demulcents are also supposed to be good for IBD, but the polysaccharides of which most are composed are what exacerbate the bacterial overgrowth we’re trying to control. For most of those who’ve come to SCD™, the prevailing wisdom about both mainstream and alternative treatments has failed them. So, while it may seem that green tea should be beneficial, it is nonetheless, not SCD™ compliant.
However, after looking carefully at the study in question, she reversed her decision and writes: I feel rather certain that green tea is OK even tho it kept company with rice and bread [in the study]. But notice, “7 or more cups per day.” I would allow green tea and limit it to 2 cups per day. You realize that I don’t know, don’t you? I have no hesitation when it comes to certain carbohydrates but these other things stump me so I try to be logical.