Hi,Good Evening.This is Dr.Savaskar from India,attending your query to my online HCM Clinic. -I studied your query in depth and Understood your health concerns. -Accordingly on the facts given by you- Causes of the Vomiting and its Treatment is as follows- a-I think your grandmother- is suffering from-severe gastritis -post-chemo .This gastritis has lead to bleeding ulcers -causing black-vomits. b-Lymphnode treatment is no way related to cause the black vomiting by your GrandMohter getting the chemo for the Advanced Ovarian Cancer with Mets in spleen and abdomen. Treatment-for it- a-Cold iced Gastric Lavage by Ryles Tube/or Gastric lavage tube-or gastric portal-to control the bleeders of Gastric Ulcers by Gastric Hypothermia-stopping the bleeding from the gastric ulcers. b-Vit Bplex with vit c- Iv supplements for the fast healing of the gastric mucosa lining cells. c-Inj.Pantoprazole-to control the inflammatory ulcers caused by the toxic drug effects on the gastric mucosal- epithelium-leading to bleeding gastric ulcers thus contolling the black vomiting. d-Sos Gastric haemo-clips for bleeding gastric ulcers by OGD route. e-Blood transfusion -SOS to recoup the blood volume I would advise you to consult your ER Onco-Physician as its alarming emergency and needs to be controlled immediately. Hope this would help you with the relief you needed. Wishing you healthy living and early recovery of this emergency. Wellcome for more queries till you get the satisfied.Thanks for your query to HCM Clinic.Have a Good Day...!! Dr.SAVASKAR M.N. M.S.GENL-CVTS, Super specialist and Senior Consultant- and Expert in Non-Curable-Disease therapy for Cancer,Asthma,etc,Rejuvenation therapy and Tissue failure -reversal therapies.