This article is more than 5 years old. Information may no longer be current.
Treating bowel dysfunction
Management of symptoms related to bowel dysfunction remains a challenge for physicians who see patients with this condition. Loss of bowel function due to involvement of mesentery, omentum or bowel is commonly seen in cancer of the stomach, pancreas, colon, appendix, ovary and lobular carcinoma of the breast.
The etiology may be mechanical obstruction, but is often due to loss of peristaltic activity (ileus) from implantation of tumor on serosal surface of bowel or within the neural network of the mesentery. The latter two etiologies may produce open but not active bowel, which creates an area of poor stool passage.
Although the functional problem is usually not amenable to surgical correction, the patient remains in distress with symptoms of nausea and vomiting if the areas that are dysfunctional are in the upper jejunum or stomach, or a constant feeling of fullness with reduced passage of stool if the site is lower. There may in fact be little passage of stool for days followed by several bowel movements.
Pain that can be constant or cramping may be present. In many instances there are mixtures of mechanical blockage and areas of slowed gut motility. Patients can describe a worsening of the pain with movement such as riding in a car; this pattern suggests peritoneal carcinomatosis.
Although these symptoms can be seen at the end of life, they may begin much further back in the illness course and the individual can still be ambulatory and otherwise relatively functional. Thus, a treatment plan may need to be modified as the disease progresses.
In general, treatment with chemotherapy or hormonal therapy — in the case of breast cancer — does not impact on these symptoms or disease burden as well as active therapy for presentations with liver or lung involvement. Issues of drug delivery, or absorption, for example, may diminish any potential benefit.
Efforts aimed at management of symptoms of bowel dysfunction fall into mechanical and pharmacological. The use of stents may avoid surgery and for selected individuals may markedly improve their symptoms if the underlying etiology is more mechanical. However, not all blockages are amenable to stents, especially in the small bowel. The use of gastric decompression by a tube and suction remains necessary for many patients. Although psychologically distressing, the benefit from relief from constant nausea or vomiting and a decrease in fullness and discomfort often outweighs the distress about the use of such devices. With techniques currently available, a tube can usually be placed percutaneously into the stomach and avoid a long-term nasogastric tube that also causes symptoms.
Medications with negative effects on peristalsis should be stopped or dose-reduced. Metabolic imbalances should be corrected, if possible. Patients who are earlier in their trajectory may benefit from the use of octreotide to reduce the obligatory daily output of the stomach. On occasion, we have been able to avoid a venting tube with this agent. The dose to be used is often lower than that with neurosecretory tumors, eg, 100 mg to 150 mg twice a day. Promotility agents may be helpful. The remaining agent that is readily available commercially in the United States is metoclopramide. This agent acts more proximally and may cause cramping in the setting of small bowel dysfunction, especially if there is mechanical blockage.
With involvement of the lower bowel, aggressive use of laxatives that are osmotic or mildly stimulatory together with stool softeners may preserve bowel function for some time, permitting the patient to be otherwise active. Other classes of drugs that have been suggested in the palliative medicine literature include steroids and anti-emetics.
Pain management requires a delicate balance between achieving ideal pain relief and further worsening the remaining bowel function. Although this problem becomes less of an issue as the condition worsens, earlier in the course, non-opioids should be considered and perhaps pushed harder than would typically be the case. The patient needs to be aware of these issues so that they understand and are willing to tolerate some pain; or use non-medical measures such as change of position, massage or heat before taking additional narcotic that may aggravate and not alleviate the symptoms. Late in the illness course, parenteral narcotics may be needed due to issues of absorption.
Dietary measures must be tempered with the need to maintain weight, and may require considerable empiricism to achieve a correct balance between calories, protein and bulk. At end of life, the use of tube feedings or parental hyperalimentation has not been shown to extend life and may worsen symptoms when bowel dysfunction is severe.
Ultimately many if not most patients will lose bowel function as an end-stage event, but careful attention to symptoms early on may permit the patient to have preservation of bowel function for some time with a favorable impact on quality of life.
Stephen A. Bernard, MD, is Professor of Medicine at the University of North Carolina, Chapel Hill.