A large proportion of the American population avails itself of a variety of complementary and alternative medicine (CAM) interventions. Allopathic practitioners often dismiss CAM because of distrust or a belief that there is no sound scientific evidence that has established its utility. However, although not widely appreciated, there are thousands of randomized controlled trials (RCTs) that have addressed the efficacy of CAM. We reviewed the RCTs of herbal and other natural products, acupuncture, and homeopathy as examples of typical CAM modalities, focusing on conditions of interest to gastroenterologists. Peppermint (alone or in combination) has supportive evidence for use in patients with dyspepsia, irritable bowel syndrome, and as an intraluminal spasmolytic agent during barium enemas or endoscopy. Ginger appeared to be effective in relieving nausea and vomiting due to motion sickness or pregnancy. Probiotics were useful in childhood diarrhea or in diarrhea due to antibiotics; one particular formulation (VSL#3) prevented pouchitis. Acupuncture appeared to ameliorate postoperative nausea and vomiting and might be useful elsewhere. There is even a suggestion that homeopathy has efficacy in treatment of gastrointestinal problems or symptoms. The major problem in interpreting these CAM data is the generally low quality of the RCTs, although that quality might not be different compared to RCTs in the general medical literature. Gastroenterologists should become familiar with these techniques; it is likely that their patients already are.