|blood in the stools|
Blood in the stools is a common complaint. It frequently arises from minor illnesses, but always needs medical attention.
The stool, normally some shade of yellow, may be discolored by the presence of blood. The blood may appear as a streak of red on the side of the stool, a few drops of blood on the stool, occurring after defecation, or as a change in the color of the entire fecal content: bright red, dusky red/ maroon, or black.
The significance of each of these types of bleed varies. The word hematochezia refers to the presence of red or reddish blood in the stool, while melena is the presence of black stools. Hematochezia occurs from a source in the small intestine, large intestine or rectum. On the other hand, blood from the first few organs in the alimentary canal, such as stomach or duodenum, presents as melena. Hematochezia is then the manifestation of what is often called lower gastrointestinal hemorrhage. Melena is the manifestation of upper gastrointestinal hemorrhage. A third presentation of blood in the stool is the presence of occult blood: blood that is not visible to the naked eye but detectable by tests.
Hematochezia is often called lower gastrointestinal hemorrhage. It is somewhat commoner than upper (which presents as melena). However while patients with upper gastrointestinal bleeding nearly always need admission, patients with lower gastrointestinal bleed only occasionally are admitted. Therefore data from hospital admissions indicates that the former is about 10 times more common than the latter. This article describes the causes, significance and treatment of hematochezia. Melena is discussed in a separate article.
causes of blood in the stools
Red blood on otherwise normal stool most often arises from the anal canal, with piles and fissure in ano being the usual causes. Fistula in ano may infrequently be associated with a little bleeding. In children polyps in the rectum often cause streaks of blood on the stools. In persons over 40 cancers must be ruled out. Blood from sources higher in the intestine colours the entire stool red, maroon or dusky. It can come from intestinal polyps, masses of veins and arteries, ulcers occurring in typhoid fever, Meckel's and other diverticulae, , ulcerative colitis, benign tumours, colonic cancers and other causes (rarely tuberculosis of the alimentary tract). Multiple tiny, tumour-like lesions of arteries and veins, called malformations, can occur in the elderly ("angiodysplasias") and bleed profusely. Grossly dilated veins called varices, can occur in liver disease, may bleed. A defect of coagulation can cause a bleed from anywhere in the body, including the intestines, and may develop after chemotherapy for cancer.
The doctor will take a detailed history, examine the patient in detail, and also perform an internal (rectal) examination with a gloved finger. In the absence of pain, the intestines need to be looked at with endoscopes. The rectum can be seen with a proctoscope. The large intestine is seen with a colonoscope, which for blood in the stool is the single most important investigation. Patients with tumours can be biopsied during colonoscopy. In a significant number of cases the patient can be treated at the time of colonoscopy. For example, polyps that are bleeding can be removed.
The small intestine is difficult to see with endoscopes, and X-rays are needed to evaluate them. X-rays to evaluate the intestines are the barium follow-through upper gastrointestinal study, and the barium enema. In the follow-through some contrast material ius given to the patient to drink, and an X-ray is taken to evaluate the small intestine. In the enema the same contrast is given from the anus to evaluate the large intestine. A few other tests are available, such as angiography and isotope scanning, but these are less effective and rarely required.
Some patients may need emergency treatment with fluids and blood. Endoscopy can also be done in an emergency. Treatment depends on the actual disease causing the bleed. The importance of gastrointestinal bleeding is not the treatment itself as much as the appropriate diagnosis, and promptness with which action is taken. Major bleeds should be managed with utmost urgency.
If the patient continues to bleed massively, and the diagnosis is not confirmed, an urgent operation is indicated, to resect the portion of the bowel that is bleeding. This may be a localized resection of the small or large bowel, or a massive resection of as much as the entire colon. Some patients will end up with a temporary or even permanent ostomy, an opening in the abdominal wall that discharges feces.
Dietary restrictions depend upon the disease. In general there are no dietary restrictions, unless feeding is completely restricted for investigation or operation.
Some drugs are now available that can control bleeding in over 50% of patients. These include vasopressin and octreotide.
Blood in the stools is serious enough to always warrant consultation. Consultation should be early rather than late.
Sood, MBBS (AIIMS), MS (AIIMS), MAMS, is a
practising surgeon attached to Dharamshila Cancer
Hospital, Sir Ganga Ram Hospital and to Noida Medicare
Center. Formerly Professor of Surgery, Himalayan
Institute of Medical Sciences, Dehradun, Dr Sood has a
special interest in gastrointestinal surgery. He has had
an active academic career, has published several papers
in national and international journals, and is the Editor
(with Dr Anurag Krishna) of a widely acclaimed book
titled Surgical Diseases in Tropical Countries.
Last revised: May 11, 2000