Use Cathartics and Diuretics with Caution in Complete Bowel Obstruction and Urinary Retention Caused by Tumors

When a tumor advances to the late stage, it is often accompanied by serious complications; complete intestinal obstruction and urinary retention are two that particularly affect the patient's quality of life. Because a tumor growing in a critical location has become too large, the patient cannot pass stool or urine normally—or only one of the two is blocked. At such times, the usual TCM approach is to use formulas such as Chengqi Decoction, Dachaihu Decoction, Wuling Powder, Zhuling Decoction, or Xiayu Xue Decoction to promote bowel movement and diuresis; in severe cases, harsh and toxic products such as Shizao Decoction, Zhouche Pills, or Pengzheng Pills are used to achieve free urination and defecation.

But for patients whose tumor has grown large enough to cause complete or near-complete intestinal obstruction and urinary retention, such treatment does more harm than good. Purgatives may not only fail to restore bowel movements but also add problems such as intestinal gas; after taking them, the patient may experience colicky abdominal pain, even profuse sweating, collapse, and fatigue. Diuretics may make urination even more difficult, worsen hydronephrosis, and cause lower abdominal urgency and back pain.

Because in these patients the obstruction and urinary retention are caused by an overgrown tumor, aside from shrinking the tumor there is no other way to truly relieve their symptoms; symptomatic supportive treatment may backfire. Purgatives promote intestinal motility; if the patient cannot pass stool or gas normally, overly rapid peristalsis easily leads to intestinal gas and worsened abdominal pain. Diuretics promote urine production; when the tumor blocks the urinary system so that urine cannot be expelled, the more urine produced, the greater the pressure on the kidneys.

These patients are best treated with integrated Chinese and Western medicine. Obstructed patients can be relieved through gastrointestinal decompression; patients with urinary retention can have a urinary catheter inserted to drain urine and reduce the burden on the kidneys. At the same time, patients who still have therapeutic value need other methods to control the tumor, shrink it as much as possible, and prolong survival. Terminal-stage patients should receive only hospice-style symptomatic supportive care to relieve suffering.

The above issues I have personally verified in clinical practice; I hope they will receive readers' attention.