A Summary of TCM Approaches to Treating Diarrhea in Cancer Patients
Cancer patients frequently develop intractable diarrhea, and the causes that trigger diarrhea in cancer patients are various. There is diarrhea caused by tumor progression, as well as diarrhea caused by the patient's own constitution, and even some diarrhea that is a side effect of treatment—for example, some patients develop diarrhea after surgery, radiotherapy, chemotherapy, Chinese medicine, or oral targeted drugs.First, many tumors, once they reach a certain stage, can damage the intestinal mucosa, leading to irregular diarrhea. For instance, some patients with intestinal cancer, neuroblastoma, or gastrinoma easily develop diarrhea because of the tumor.Second, some patients have a phlegm-dampness constitution due to spleen-kidney yang deficiency or other causes, and already had chronic diarrhea before the tumor was diagnosed—for example, patients diagnosed by Western medicine with colitis.Diarrhea caused by treatment is also very common; surgery, radiotherapy, chemotherapy, Chinese medicine, and targeted drugs can all cause diarrhea in some patients.After gastrointestinal tumors are surgically removed along with part of the intestinal segment, intestinal function changes and diarrhea easily appears. Chemotherapeutic drugs are toxic to the intestinal wall; they can interfere with intestinal cell division, cause necrosis of intestinal wall cells and inflammation of the intestinal wall, and form diarrhea. Radiotherapy of the abdomen, pelvis, or lumbar spine easily leads to radiation enteritis and secondary atrophy of the intestinal mucosa, causing acute exudative diarrhea. The side effects of radiotherapy sometimes do not appear immediately; some patients even develop sequelae of radiotherapy only many years later. Side effects of targeted drugs such as Tarceva (erlotinib) and Sorafenib can also cause adverse reactions such as diarrhea. Cold- and bitter-natured Chinese herbs, as well as some drugs with liver and kidney toxicity, can also cause diarrhea reactions in patients.Diarrhea in cancer patients is generally lingering, with a long disease course; after prolonged illness, complex conditions of mixed cold and heat often appear, making treatment extremely tricky. The conventional Western medicines for symptomatic treatment of diarrhea are diphenoxylate, loperamide (Imodium), atropine, and smectite powder, but such medications rarely have a curative effect on intractable diarrhea, and long-term use carries certain side effects.Chinese medicine treats diarrhea through pattern differentiation and treatment (bianzheng lunzhi); one should analyze the cause of each patient's diarrhea concretely according to their specific situation and prescribe the appropriate herbs. It is not possible rashly to give a unified treatment plan for diarrhea, nor to prescribe a corresponding Chinese herbal formula merely on the basis of a disease name diagnosed by Western medicine.First we need to understand the patient's previous constitutional characteristics. If the patient has a spleen-kidney yang-deficiency constitution, the first priority is to warm and tonify kidney yang; if the patient has a damp-heat constitution, the approach should be to eliminate dampness and heat. There are also some patients whose diarrhea results from severe organ damage; at such a point various treatments may be unable to relieve the condition, and one should honestly tell the patient and the family.But whatever the cause of the diarrhea, the TCM approach to treating it follows certain rules. Based on my many years of reading and practical experience, I will discuss my own thinking on the pattern differentiation and treatment of diarrhea.
From the TCM perspective, diarrhea roughly has four patterns: wind-cold intrusion, spleen-deficiency diarrhea, kidney-deficiency diarrhea, and damp-heat diarrhea.
Patients with wind-cold intrusion generally also have an exterior pattern, or a prior history of being struck by wind and cold; such patients usually also have aversion to cold and should be treated with formulas such as Gegen Tang (Pueraria Decoction) or Guizhi Jia Gegen Tang (Cinnamon Twig plus Pueraria Decoction). Gegen-series formulas are quite commonly used to treat diarrhea.Both Guizhi Jia Gegen Tang and Gegen Tang present the symptom of 'spontaneous diarrhea,' but the root of such patients' diarrhea lies not in the 'interior' but in the 'exterior'; these patients all belong to exterior deficiency with failure to secure the exterior, with the pathogen entering the interior. Therefore treatment still mainly follows the approach of acrid-warm exterior-releasing, with the moderate addition of Pueraria, which stops diarrhea, to achieve the therapeutic effect.
Gegen Tang formula: Pueraria (gegen) 20 g, Ephedra (mahuang) 15 g, Cinnamon Twig (guizhi) 10 g, White Peony (baishao) 10 g, honey-fried Licorice (zhigancao) 6 g, fresh Ginger (shengjiang) 5–7 slices, Jujube (dazao) 5–7 pieces.
Guizhi Jia Gegen Tang formula: Pueraria (gegen) 20 g, Cinnamon Twig (guizhi) 10 g, White Peony (baishao) 10 g, honey-fried Licorice (zhigancao) 6 g, fresh Ginger (shengjiang) 5–7 slices, Jujube (dazao) 5–7 pieces.
If the patient does not sweat easily or even has no sweat at all, with severe aversion to cold, use Gegen Tang. If the patient sweats easily and has aversion to cold, use Guizhi Jia Gegen Tang. After using Gegen Tang and the patient has sweated, do not use Gegen Tang again; instead, continue with Guizhi Jia Gegen Tang to consolidate the recovery. For patients with chronic diarrhea, if diarrhea is not completely stopped after the exterior-releasing Gegen Tang or Guizhi Jia Gegen Tang, they should be followed up with the Chinese patent medicine Yupingfeng Granules (Jade Screen Powder) for consolidation.
Patients with spleen-deficiency diarrhea often have signs of retained water-dampness; besides diarrhea, they may have a enlarged, pale, water-glossy tongue with teeth marks, and long-term loose, soft, unformed stools. Such patients should be treated mainly with formulas that fortify the spleen and stop diarrhea, such as Shenling Baizhu Granules (Ginseng, Poria and Atractylodes Powder), Sijunzi Tang (Four-Gentlemen Decoction), Liujunzi Wan (Six-Gentlemen Pill), and Xiangsha Liujun Wan (Costus-Ammomum Six-Gentlemen Pill).For example, in summer, spleen deficiency with internal dampness, combined with the summer pathogen of dampness and the side effects of raw and cold fruits eaten in summer, often produces diarrhea of mixed dampness and heat, and even symptoms of vomiting and diarrhea. At such times one can use Huoxiang Zhengqi Wan (Agastache Orthostatic Pill), Pingwei Wan (Calm the Stomach Pill), or Xiangsha Pingwei Wan (Costus-Ammomum Calm the Stomach Pill).Patients with decline of kidney yang easily develop aching and weakness of the lower back and knees, long-term diarrhea, or even 'five-dawn diarrhea' (wugengxie). The treatment of such patients should follow the approach of warming and tonifying kidney yang while also stopping diarrhea. Representative formulas are Sishen Wan (Four-Spirit Pill), Guifu Dihuang Wan (Cinnamon-Aconite Rehmannia Pill), Guchang Capsules (Intestine-Fixing Capsules), and Jinkui Shenqi Wan (Golden Cabinet Qi-Boosting Pill).Diarrhea caused by a damp-heat constitution or by damp-heat pathogen usually has an abrupt onset, with dozens of bowel movements a day, and a clear history of food or drug allergy. The treatment of such patients should be based on Coptis-series formulas. The patent medicines include berberine tablets, compound berberine tablets, Fuke'an tablets, and Xianglian Wan (Costus-Coptis Pill); the decoctions include Huanglian Jiedu Tang (Coptis Detoxification Decoction) and Gegen Qinlian Tang (Pueraria, Coptis and Scutellaria Decoction).Huanglian Jiedu Tang formula: Coptis (huanglian) 6 g, Phellodendron (huangbo) 6 g, Scutellaria (huangqin) 9 g, Gardenia (zhizi) 9 g.Gegen Qinlian Tang formula: Pueraria (gegen) 15 g, Coptis (huanglian) 9 g, Scutellaria (huangqin) 9 g, honey-fried Licorice (zhigancao) 6 g.A thousand prescriptions are easy to obtain, but one effective result is hard to find. Intractable diarrhea is not easy to treat; in treating intractable diarrhea I myself have also failed repeatedly. But using TCM pattern differentiation, I have also resolved the diarrhea problems of many patients. Once a patient develops acute symptoms such as diarrhea, the patient and family are emotionally impatient and irritable, so the physician must proceed cautiously in treatment.