Side effects of excess consumption of yellow dock may include excessive urination, nausea and diarrhea.

Diarrhea, nausea or vomiting, skin eruptions, kidney damage (blood in urine, decreased urine flow, swelling of hands and feet).

Avoid if you have any chronic disease of the gastrointestinal tract.

A case of fatal poisoning due to ingestion of the plant Rumex crispus is described. The patient, a 53-year-old male, presented with gastrointestinal symptoms, severe hypocalcemia, metabolic acidosis and acute hepatic insufficiency. Despite therapeutic measures, the patient died 72 h after ingestion of the plant material. Noteworthy among the pathological findings were centrolobular hepatic necrosis and birefringent crystals in the liver and kidneys that were identified by histochemical techniques and scanning electron microscopy. These observations are compared with other reports in the medical literature, with an emphasis on the risk involved in the use of these plants for culinary or medicinal purposes.

– Vet Hum Toxicol 1990 Oct;32(5):468-70 — Fatal poisoning by Rumex crispus (curled dock): pathological findings and application of scanning electron microscopy. — Reig R, Sanz P, Blanche C, Fontarnau R, Dominguez A, Corbella J. — Department of Public Health, School of Medicine, University of Barcelona, Spain.

Excessive use of yellow dock may lead to laxative-like side effects such as stomach cramping and diarrhea. Yellow dock also contains oxalic acid, an acidic phytochemical. Oxalic acid reportedly can interfere with normal calcium levels in the blood, leading to complications with blood coagulation. Yellow dock has caused dermatitis in livestock that have eaten it. There have been several cases of animal deaths from oxalate poisoning.

– Panciera RJ; Martin T; Burrows GE; Taylor DS; Rice LE. Acute oxalate poisoning attributable to ingestion of curly dock (Rumex crispus) in sheep. J Am Vet Med Assoc. 1990. 196(12):1981-4.