While abdominal tuberculosis is a relatively rare condition in developed countries, it is still seen commonly in developing nations. It is reported that abdominal tuberculosis occurs in about 10-30% of all patients suffering from pulmonary tuberculosis.
Tuberculosis can affect any part of the gastrointestinal tract, although the ileum and the ileocaecal area are involved more commonly. It can also affect the liver, the mesenteric lymph nodes present in the gastrointestinal tract and the peritoneum.
It is reported that in the gastrointestinal tract, the other sites affected (in decreasing order of frequency) are the appendix, colon, jejunum, rectum, duodenum and anal canal. The stomach is relatively resistant to TB infection.
There is a predilection for the ileocaecal region to be affected in Abdominal TB because of:
Abundance of lymphoid tissue therein (Peyer’s patches)
Increase rate of fluid and electrolyte absorption
Minimal digestive activity, which permits a greater contact time between the organism and gastrointestinal mucosa.
The pathogenesis of abdominal TB can be primary or secondary: Primary form: In this form, it is believed that the site of primary infection is the gastrointestinal tract, particularly due to consumption of dairy products which are not pasturised. In these cases, the primary lesion is in the bowel wall and the mesenteric lymph nodes. The lymph nodes enlarge and get matted together. If they rupture, infection spreads into the peritoneal cavity (peritoneal TB) and effusion occurs (ascites). The adhesion of lymph nodes to bowel may cause obstruction. Fistulae may occur between the bowel and the bladder, or the bowel and the abdominal wall.Secondary form: In this form, patients with primary pulmonary TB swallow their sputum, which can infect the intestinal wall and cause ulceration. Fistulae may occur as described earlier. Infection may spread to the abdominal cavity (peritoneal TB) and cause ascites.Peritoneal TB can also occur secondary to infection of the mesenteric nodes that are infected via haematogenous spread from the primary focus. Liver affection can also occur through haematogenous spread from the primary focus and it invariably occurs in military tuberculosis.
In tubercular peritonitis, ascites is frequently seen; tubercles are scattered throughout the omentum, bowel wall and other organs. The mesentery is usually thickened and oedematous, and there may be collections of pus or caseous masses. Signs of perforation, obstruction or fistulae formation may be apparent.
In tuberculosis of the liver, there may be diffuse infiltration with tubercles giving a military appearance, solitary abscesses may also develop. Alternatively, there may be tuberculous micro-abscesses throughout the liver. Occasionally, tuberculous masses (pseudo-tumours) may occur.
Symptoms of abdominal TB are very vague and non-specific. The patient presents with loss of appetite, loss of weight, abdominal pain, nausea and vomiting, constipation or diarrhea, fever and night sweats. Sometimes, on examination, soft abdominal masses can be felt. There is often associated ascites, hepatosplenomegaly and lymphadenopathy. Patients may sometimes present with symptoms of intestinal obstruction (acute abdominal pain and abdominal distension).
Abdominal TB should be suspected in any patient who is losing weight, has fever, vague abdominal pain and has an abdominal mass and fluid in the abdomen.
Diagnosis is usually based on the clinical features. Additionally, the following investigations may be helpful: X-ray of the bowel showing thickened bowel, ascites, calcified mesenteric lymph nodes or calcified hepatic granuloma. Barium Meal follow through may reveal accelerated transit time, hypersegmentations and flocculation of barium as the earliest signs. Thickening of the mucosal folds, ulceration and obstruction will also be revealed by this procedure. Barium Enema may show annular constriction and patulous ileo-caecal valve, ulceration and polynoid mass Biopsy of lymph node, peritoneum or liver. Culture of material from aspiration of liquid from the abdominal cavity, or pus from sinuses. Ultrasound of abdomen is a very valuable tool wherein ascites, calcified granulomas, matted bowel loops, mesenteric lymphadenopathy and intestinal obstruction can be detected.
Colonoscopy is a valuable diagnostic procedure for ileo-caecal tuberculosis. It allows obtaining tissue specimens for bacteriological and histological examinations
Chemotherapy is the mainstay of treatment, using standard regimens. Some authors recommend a longer duration of therapy, however, i.e. for nine or twelve months. Patients who have obstruction, perforation, fistulas or strictures require surgery. On some occasions, healed disease may leave adhesions or scarring which can subsequently cause intestinal obstruction. This may require surgery. There are varied views on the role of corticosteroids in this condition. Some authors report their benefits in reducing inflammation and fibrosis, and in facilitating resolution of ascetic fluid.
The prognosis of abdominal TB is usually favourable if patients have complications like perforation, the prognosis is still favourable with surgical management Tuberculosis of the Gastrointestinal Tract Tuberculosis is a chronic infection caused by Mycobacterium tuberculosis. M. bovis, which earlier accounted for a substantial number of cases worldwide, is now less frequently encountered due to widespread pasterurisation even in neolithic times. However, the disease became epidemic during the industrial revolution, which produced crowded living conditions favourable to its spread. With the advent of an effective vaccine and chemotherapeutic agents, tuberculosis has now become less common in India, and rare in the developed countries.
Tuberculosis is one of the most important causes of morbidity and mortality in India. The common forms of tuberculosis encountered in our country are pulmonary tuberculosis and tuberculosis cervical lymphadenopathy. 15 to 30 per cent of patients suffering from pulmonary tuberculosis develop abdominal tuberculosis. With the growing incidence of HIV infection the incidence of abdominal tuberculosis has also increased. The outcome of such patients is quite fatal. Diagnosis of abdominal tuberculosis at times poses a lot of problems. The treatment of this condition is mainly medical. Surgical intervention is called if complications supervene.
The abdomen is involved in 10% to 30/5 of patients with pulmonary tuberculosis. The diagnosis is not difficult in societies where the disease is common and clinicians are aware of it. While previously rare in Western countries, the incidence is now rising among immigrants, and patients with AIDS. In HIV-infected patients, the disease is of a rapidly progressive nature, often fatal though usually treatable, but the diagnosis is difficult and often delayed. Treatment is essentially medical but occasionally surgical opetaion is necessary.
Tuberculosis is still common in the developing world, so common that it must be considered in the differential diagnosis of a majority of the medical, surgical and gynaecological presentations. Abdominal tuberculosis too is quite common. Two large series from the UK have reported the prevalence in Asian immigrants as 16 and 36 per 100,000 population. While abdominal tuberculosis is one of the commonest forms of e’xtra-pulmonary tuberculosis, it is ill understood and is being neglected all too often by clinicians and researchers. Surprisingly, even some text books on infectious diseases and a monograph on inflammatory bowel disease make no mention of abdominal tuberculosis
Abdominal tuberculosis was common in the United Kingdom in the 18th and 19th centuries and in the first half of the 20th century. During the 1950’s the recognition of Crohn’s disease, the use of streptomycin and other drugs, and the pasteurization of milk led to the virtual appearance of abdominal tuberculosis in the western world. During the last two decades a new type, mycobacterium tuberculosis hominis, has appeared mainly in the immigrant population, especially those from the Indian subcontinent. A retrospective review of 68 patients with abdominal tuberculosis is presented. The pathology, diagnosis and management of these cases is discussed, together with the differential diagnosis of Crohn’s disease It is suggested that the immigrant brings the disease into the United Kingdom in his mesenteric glands and that the disease is reactivated or `revived’ at some later date due to some modification of the immune process.