Cowherb, also known as Vaccaria segetalis (or Vaccaria hispanica), is primarily used in traditional Chinese medicine (TCM) rather than on the basis of strong scientific validation. In TCM, Cowherb seeds (also called Wang Bu Liu Xing) are traditionally employed to promote the circulation of blood and alleviate conditions like abdominal pain, especially when it is believed to be related to blood stasis or menstrual disorders. Its usage is documented in classical herbal texts, where it is often included in formulas aimed at treating abdominal pain due to its blood-invigorating properties.

However, modern scientific evidence supporting Cowherb's efficacy for abdominal pain is limited. Most available data are preclinical, focusing on its potential anti-inflammatory and analgesic effects in animal or cellular models. Direct clinical trials evaluating its effectiveness for abdominal pain in humans are lacking. Therefore, the evidence rating is moderate for traditional use but low from a scientific standpoint. Most support comes from case reports, traditional literature, and its continued inclusion in TCM formulas rather than randomized controlled trials or pharmacological studies in humans.

In summary, Cowherb's use for abdominal pain is justified by a long history of traditional use in TCM rather than robust scientific evidence. Individuals considering its use should consult with a qualified healthcare provider, especially given the lack of substantial clinical research.