B. J. Surge Vole 66 (1979) 630-632
Fulminating amoebic colitis: a clinical evaluation T. V A J R A B U K K A , A. D H I T A V A T , B. K I C H A N A N T A , Y . S U K O N T H A M A N D , C. T A N P H I P H A T A N D S. V O N G V I R I Y A T H A M * groups. One patient (Case 10) had a previous history of treated amoebic dysentery and remained asymptomatic until the present attack. All except 2 patients appeared t o be in good health previously. Of the 2 debilitated patients one was a young heroin addict who contracted the disease while in prison (Case 4). This patient had had diarrhoea for 4 months and may have been malnourished before the colitis. The other ill patient (Case 11) was an elderly man with congestive cardiac failure. In all but Case 4, already referred to, there was only a short history of diarrhoea, varying from 2 days to 3 weeks. In one patient (Case 3), whose disease was confined to the right colon, there was no history of diarrhoea. The onset of diarrhoea was usually abrupt with 5-15 stools per day and was associated with toxaemia and abdominal tenderness. In some patients (Cases 6 and 7 ) the diarrhoea was watery and explosive initially, simulating acute bacillary dysentery. Many patients (Cases 1, 2, 6, 7 and 9) denied the presence of blood in the stools but red and white blood cells were often found on microscopic examination. In most cases mucus was present and mixed with a small amount of loose stool with each bowel action. As the disease progressed the toxaemia and the frequency of the diarrhoea increased. Eventually the diarrhoea consisted of continuous passage of copious white glairy mucus exudate mixed with occasional AMOEBIASIS is endemic in Thailand and amoebic necrotic casts of mucosa. colitis is normally a mild disease which responds well In spite of very severe colitis, amoebae could not be to medical treatment. Fulminating or necrotizing demonstrated on initial microscopic examinations of amoebic colitis is an unusual form of amoebic colitis the stools in 7 of 8 patients. Subsequent stool examinacharacterized by severe toxaemia, rapid and extensive tions revealed numerous amoebae in 2 of these 7 colonic necrosis and multiple perforations. Because patients. Hence preoperative confirmation of amoebic of its rarity the disease is not generally recognized colitis was possible on the basis of stool examination before irreversible colonic necrosis occurs and is in 3 patients only (Cases 1, 4 and 5); in only 2 (Cases almost invariably fatal. It is the purpose of this paper 4 and 5 ) was there sufficient time to commence antito present our experience in the diagnosis and manage- amoebic treatment. One patient (Case 11) received ment and to show that when surgical intervention is preoperative anti-amoebic therapy for suspected timely and adequate the prognosis of this once grave giardiasis. condition is vastly improved. The progress t o colonic gangrene and peritonitis was rapid, varying from 4 days to 3 weeks in most patients Patients and methods From 1974 to 1978 inclusive 1 1 patients with fulminating and after a chronic course of 4 months in only 1 patient amoebic colitis were treated in the surgical department, (Case 4). In most patients there was no dramatic turnChulalongkorn Hospital, Bangkok. The amoebic nature of the ing point to indicate the onset of gangrene of the colon. colitis was confirmed by the demonstration of Entamoeba The clinical picture was that of gradual deterioration hiuto/ytica in the stools or in the resected colonic tissues in 10 as indicated by the worsening of toxaemia, abdominal patients and by a positive specific serological test in one patient. distension, tenderness and diarrhoea. Only when I n those who presented with diarrhoea laboratory tests included peritonitis had become fully established was gangrene stool examination and culture, serological tests for enteric of the colon with rupture recognized. A delay in fever and blood culture. All I 1 patients underwent exploratory laparotomy and received intensive postoperative supportive recognition of colonic gangrene of up to 2 days treatment including parenteral antibiotics (penicillin o r occurred in 8 patients, up to 3 days in 2 patients (Cases chloramphenicol with gentamicin or kanamycin), fluid and 4 and 6 ) and 4 days in 1 patient (Case 11).
SUMMARY
Eleven cases of’fulminating amoebic colitis seen in 5 years are reported. Only people of low socioeconomic status were affected and most were in good health previous1.v. The disease appeared to jollo w a fulminant course f i o m the onset und was rarely a secondary phenomenon superimposing on the chronic amoebic dysentery. The diagnosis was dificult due to severe systemic manifestations and the periodic absence of Entamoeba histolytica in the stool. The development of colonic necrosis was often masked by the severe preexisting local signs andperforation could occur in spite of adequate anti-amoebic therapy. Mortality was related to late diagnosis, delayed recognition of irreversible colonic necrosis and inadequate surgical treatment. To reduce the present 55 per cent mortality further it i s proposed that, in an endemic area, early specific antiamoebic therapy is justified in severe and undiagnosed colitis. Euen under specific anti-amoebic treatment the patient with severe amoebic colitis remains a potential surgical candidate. Surgery is indicated when the patient continues to deteriorate in spite of the therapy, when there is an acute episode which signifies perforation, or when severe diarrhoea, toxaemia and abdominal tenderness persist ajier a full course of specific anti-amoebic therapy. Primary total resection of the diseased colon is the treatment of choice.
electrolyte replacement and blood transfusion when indicated. When the diagnosis of amoebiasis was made the patients were given either dehydroemetine or metronidazole o r both.
Results The clinical features are shown in Table 1. The patients in this series belonged to the low socioeconomic
Operative findings and management The inflamed and extremely friable colon was usually found wrapped in omentum and adherent to the
* Department of Surgery, Chulalongkorn Hospital, Saladang, Bangkok, Thailand.
Fuhninatiog amoebic colitis Table I: FEATURES OF 11 CASES OF FULMINATING COLITIS Duration Adm. Op. to Age/Sex before E. hist. toop. death No. (yr) adm. (d) in stool Preop. diagnosis (d) (d) Extent of necrosis ~~
+
Typhoid
4
-
-
Bacillary dysentery Appendix abscess
2 3
4 14
+ +
Amoebic colitis Amoebic colitis
4 6
-
1
60/F
20
2 3
29/F 71/M
2 10
4 5
44lM 39/F
120 10
6
3/M
6
7
85/M
14
8
58/F
10
9
50/F
5
-
71/M
7
-
2. Amoebic colitis Amoebic colitis
2. 8
10
0
-
11
60/M
14
-
Giardiasis
1. 5 2. 15 3. 17
21
-
-
Bacillary dysentery Bacillary dysentery Peritonitis
1. 7 2. 10 2
0
14
14
5
-
1. Appendix abscess 1. 4
Entire colon
Procedure
Total colectomy, ileostomy and closure of rectal stump Entire colon Caecostomy, drainage Entire colon except Subtotal colectomy, distal sigmoid ileostomy and mucous fistula Entire colorectum Panproctocolectomy Entire colon Total colectomy, ileostomy and mucous fistula Caecum to 1. Caecostomy descending colon 2. Drainage Entire colon Total colectomy, ileostomy and closure of rectal stump Caecum to midRight colectomy transverse colon 1. Caecostomy, ileoCaecum to midtransverse colon transverse bypass 2. Right colectomy Entire colon except Subtotal colectomy, distal sigmoid ileostomy and mucous fistula 1. Drainage 2. Ileostomy Entire colon 3. Total colectomv
631
Result Surv. Died Died Died Surv.
Died Died Surv.
Surv. Surv.
Died
Adm., admission; op., operation; E. hist., Entamoeba histolytica; surv., survived.
inflamed parietal peritoneum. There were areas of full-thickness colliquative necrosis and areas with relatively normal serosa concealing complete mucosal necrosis. Perforations were usually multiple and widely distributed. Many perforations were partially concealed in the inflamed omental envelope and became evident as soon as the colon was touched. In more severe cases long necrotic segments of the colon had completely disintegrated with free spillage of content. The extent of colonic involvement was as shown in Table 1. Conservative surgery, i.e. drainage with external faecal diversion or internal bypass, was performed in 3 patients (Cases 2, 6 and 9) with disastrous consequences. It resulted in rapid deterioration due to spreading colonic necrosis in spite of specific anti-amoebic treatment. One of these patients (Case 2) died within 4 days of the operation from severe toxaemia, 2 patients required re-exploration because of peritonitis and only 1 patient (Case 9) survived after a colonic resection. Conservative surgery was used as a temporary procedure in 1 patient (Case 11) in the hope that the patient might improve sufficiently to allow colonic resection later. There was no improvement and the patient died after colectomy. Resection of the diseased colon with external faecal diversion and abdominal drainage was performed in 7 patients and 4 survived. Mortality Six patients in this series died, giving an overall mortality of 55 per cent. Early postoperative deaths were due to shock and toxaemia while late deaths were due to sepsis. The mortality rate was 75 per cent among those who had conservative surgery such as diversion and drainage as the primary procedure and
43 per cent for those who had resection with exteriorization as the primary procedure. The mortality was related to the extent of colonic necrosis. When the disease was confined to the area proximal to the midtransverse colon the mortality was 33 per cent compared with 57 per cent with more distal colonic involvement and 100 per cent with entire colorectal involvement. Mortality was also related to the preoperative condition of the patients. Among those with a poor preoperative state, as characterized by persistent shock (systolic blood pressure below 100 mmHg), associated cardiopulmonary insufficiency, electrolyte imbalance and hypoproteinaemia with generalized oedema, the mortality was 80 per cent compared with 33 per cent in those in a better preoperative condition. Delay of more than 48 h in the diagnosis of colonic necrosis and peritonitis also resulted in a mortality of 67 per cent, twice as high as in those with an earlier diagnosis (38 per cent). Discussion Fulminating amoebic colitis has been observed in debilitated subjects who are suffering from malnutrition, chronic illnesses and intestinal infections (Adams and Maegraith, 1960). In an area where amoebiasis is endemic, infestation with various intestinal parasites is also rife. The role of these parasites in the pathogenesis of fulminating amoebic colitis is not known. Their association in many of our cases, together with the low socioeconomic background of the patients, is indicative of the poor hygiene and low standard of health of these people. Similar predisposing factors have been observed by others (Palaez et al., 1966). The diagnosis of amoebic colitis normally rests on the typical history of bloody mucous diarrhoea,
632
T. Vajrabukka et al.
proctoscopic or sigmoidoscopic observation of of the colitis must be resisted. Severe amoebic colitis typical amoebic ulcers and, particularly, the demon- may require operation at any stage and anti-amoebic stration of E. histolytica in the stools and mucus. In drugs cannot prevent a necrotic colon from sloughing fulminating amoebic colitis the diagnosis is difficult even if all amoebae have been eradicated (Stein and because of its unusual presentation. The disease runs Bank, 1970; Mukerjee and Nigam, 1975). We agree a fulminating course in most patients, with diarrhoea with Stein and Bank (1970) that persistent diarrhoea, of varying severity. The diagnosis on clinical history abdominal tenderness and severe toxaemia, despite is relatively easy only in the rare event of the disease adequate anti-amoebic therapy, are indicative of severe superimposing upon the chronic form of amoebic colonic necrosis and the need for operation. Our results suggest that there is no place for concolitis. Sigmoidoscopy is difficult because of the almost continuous passage of mucus and because the servative surgery, particularly in undiagnosed or unfriability of the colon makes it hazardous. When treated patients. It has long been known that diversion, performed gently and skilfully without air insufflation, or diversion alone, seems to accentuate the sloughing sigmoidoscopy may provide a diagnosis in a limited of the necrotic colon (Manson-Bahr, 1939). The best number of patients with rectal or sigmoid involve- operative treatment is primary resection of the diseased ment. The curious periodic absence of amoebae in bowel with exteriorization of the ends in all patients the stools further compounds the diagnostic difficulty who are fit for laparotomy. In the past fulminating amoebic colitis always and much valuable time is lost in pursuing alternative diagnoses such as bacillary dysentery, typhoid or even carried a mortality approaching 100 per cent, whatidiopathic ulcerative colitis, which is very rare in ever the form of operative treatment (Hawe, 1945; Thailand. By the time amoebiasis is confirmed it is Rives et al., 1955; Palaez et al., 1966; Chen et al., often too late to commence effective anti-amoebic 1971 ; Sharma et al., 1975). This was due to the poor therapy. We feel that in an area where amoebiasis is preoperative state as a result of delay or inadequate endemic a trial of anti-amoebic therapy is worth while surgical treatment or both. The overall mortality in in patients with severe, undiagnosed colitis. In such this series is 55 per cent and indicates that fulminating instances the diagnosis must depend first upon the amoebic colitis is not inevitably fatal. It is our contentherapeutic response and later on the result of specific tion that we can reduce the mortality further by serological tests. Prompt anti-amoebic therapy may employing a high degree of suspicion, prompt antiarrest the progress towards irreversible colonic amoebic therapy, careful clinical evaluation and, if necrosis in some patients and in others may improve there is not rapid improvement, adequate resectional the prognosis should surgery become necessary. The surgery. cardiac toxicity of emetine makes it unsuitable in many patients who are already hypotensive from References toxaemia; metronidazole is much safer and equally ADAMS A. R. D. and MAEGRAITH B. G. (1960) Clinical Topical Diseases, 2nd ed. Oxford, Blackwell Scientific, p. 8. effective. The detection of colonic necrosis without perfora- CHEN w. J., CHEN K. M.and LIN M. (1971) Colon perforation in Arch. Surg. 103, 676-680. tion is difficult in fulminating amoebic colitis because HAWEamoebiasis. P. (1945) The surgical aspect of intestinal amoebiasis. its development is insidious and is usually masked by Surg. Gynecol. Obstet. 81, 387-404. severe preexisting local signs and toxaemia. Mucous MANSON-BAHR P. H. (1939) The Dysenteric Disorders. London, diarrhoea often continues in the presence of colonic Cassell. necrosis and peritonitis. By the time perforation is MUKERJEE s. and NIGAM N. (1975) Amoebic perforation of the colon. Am. J. Proct. 26, 57-63. recognized from the X-ray evidence of free air under the diaphragm the patients are usually very ill from PALAEZ M., VILLAZON A. and ZARABOSO R. s. (1966) Amoebic perforation of the colon. Dis. Colon Rectum 9, 356-362. toxaemia, making operation hazardous. Clearly every J. D., HEIBNER w. c. and POWELL J. L. (1955) The surgical effort must be made to detect the stage of irreversible RIVEScomplications of amoebiasis of the colon. Surg. Clin. colonic necrosis and to operate before the patient’s North Am. 35, 1421-1426. condition becomes precarious. This requires an SHARMA B. D . , CHOORAMANI s. and AGARWAL A. K. (1975) Acute awareness of the diagnosis and vigilant monitoring of amoebic necrosis of bowel. Am. J. Proct. 26, 57-62. the vital signs, abdominal girth, tenderness, severity STEIN D. and BANK s. (1970) Surgery in amoebic colitis. Gut 11, 941-946. of diarrhoea and frequent abdominal X-rays to detect dilated featureless coIon (toxic megacolon). False optimism on the confirmation of the amoebic nature Paper accepted 19 April 1979.
Fulminating amoebic colitis: a clinical evaluation T. V A J R A B U K K A , A. D H I T A V A T , B. K I C H A N A N T A , Y . S U K O N T H A M A N D , C. T A N P H I P H A T A N D S. V O N G V I R I Y A T H A M * groups. One patient (Case 10) had a previous history of treated amoebic dysentery and remained asymptomatic until the present attack. All except 2 patients appeared t o be in good health previously. Of the 2 debilitated patients one was a young heroin addict who contracted the disease while in prison (Case 4). This patient had had diarrhoea for 4 months and may have been malnourished before the colitis. The other ill patient (Case 11) was an elderly man with congestive cardiac failure. In all but Case 4, already referred to, there was only a short history of diarrhoea, varying from 2 days to 3 weeks. In one patient (Case 3), whose disease was confined to the right colon, there was no history of diarrhoea. The onset of diarrhoea was usually abrupt with 5-15 stools per day and was associated with toxaemia and abdominal tenderness. In some patients (Cases 6 and 7 ) the diarrhoea was watery and explosive initially, simulating acute bacillary dysentery. Many patients (Cases 1, 2, 6, 7 and 9) denied the presence of blood in the stools but red and white blood cells were often found on microscopic examination. In most cases mucus was present and mixed with a small amount of loose stool with each bowel action. As the disease progressed the toxaemia and the frequency of the diarrhoea increased. Eventually the diarrhoea consisted of continuous passage of copious white glairy mucus exudate mixed with occasional AMOEBIASIS is endemic in Thailand and amoebic necrotic casts of mucosa. colitis is normally a mild disease which responds well In spite of very severe colitis, amoebae could not be to medical treatment. Fulminating or necrotizing demonstrated on initial microscopic examinations of amoebic colitis is an unusual form of amoebic colitis the stools in 7 of 8 patients. Subsequent stool examinacharacterized by severe toxaemia, rapid and extensive tions revealed numerous amoebae in 2 of these 7 colonic necrosis and multiple perforations. Because patients. Hence preoperative confirmation of amoebic of its rarity the disease is not generally recognized colitis was possible on the basis of stool examination before irreversible colonic necrosis occurs and is in 3 patients only (Cases 1, 4 and 5); in only 2 (Cases almost invariably fatal. It is the purpose of this paper 4 and 5 ) was there sufficient time to commence antito present our experience in the diagnosis and manage- amoebic treatment. One patient (Case 11) received ment and to show that when surgical intervention is preoperative anti-amoebic therapy for suspected timely and adequate the prognosis of this once grave giardiasis. condition is vastly improved. The progress t o colonic gangrene and peritonitis was rapid, varying from 4 days to 3 weeks in most patients Patients and methods From 1974 to 1978 inclusive 1 1 patients with fulminating and after a chronic course of 4 months in only 1 patient amoebic colitis were treated in the surgical department, (Case 4). In most patients there was no dramatic turnChulalongkorn Hospital, Bangkok. The amoebic nature of the ing point to indicate the onset of gangrene of the colon. colitis was confirmed by the demonstration of Entamoeba The clinical picture was that of gradual deterioration hiuto/ytica in the stools or in the resected colonic tissues in 10 as indicated by the worsening of toxaemia, abdominal patients and by a positive specific serological test in one patient. distension, tenderness and diarrhoea. Only when I n those who presented with diarrhoea laboratory tests included peritonitis had become fully established was gangrene stool examination and culture, serological tests for enteric of the colon with rupture recognized. A delay in fever and blood culture. All I 1 patients underwent exploratory laparotomy and received intensive postoperative supportive recognition of colonic gangrene of up to 2 days treatment including parenteral antibiotics (penicillin o r occurred in 8 patients, up to 3 days in 2 patients (Cases chloramphenicol with gentamicin or kanamycin), fluid and 4 and 6 ) and 4 days in 1 patient (Case 11).
SUMMARY
Eleven cases of’fulminating amoebic colitis seen in 5 years are reported. Only people of low socioeconomic status were affected and most were in good health previous1.v. The disease appeared to jollo w a fulminant course f i o m the onset und was rarely a secondary phenomenon superimposing on the chronic amoebic dysentery. The diagnosis was dificult due to severe systemic manifestations and the periodic absence of Entamoeba histolytica in the stool. The development of colonic necrosis was often masked by the severe preexisting local signs andperforation could occur in spite of adequate anti-amoebic therapy. Mortality was related to late diagnosis, delayed recognition of irreversible colonic necrosis and inadequate surgical treatment. To reduce the present 55 per cent mortality further it i s proposed that, in an endemic area, early specific antiamoebic therapy is justified in severe and undiagnosed colitis. Euen under specific anti-amoebic treatment the patient with severe amoebic colitis remains a potential surgical candidate. Surgery is indicated when the patient continues to deteriorate in spite of the therapy, when there is an acute episode which signifies perforation, or when severe diarrhoea, toxaemia and abdominal tenderness persist ajier a full course of specific anti-amoebic therapy. Primary total resection of the diseased colon is the treatment of choice.
electrolyte replacement and blood transfusion when indicated. When the diagnosis of amoebiasis was made the patients were given either dehydroemetine or metronidazole o r both.
Results The clinical features are shown in Table 1. The patients in this series belonged to the low socioeconomic
Operative findings and management The inflamed and extremely friable colon was usually found wrapped in omentum and adherent to the
* Department of Surgery, Chulalongkorn Hospital, Saladang, Bangkok, Thailand.
Fuhninatiog amoebic colitis Table I: FEATURES OF 11 CASES OF FULMINATING COLITIS Duration Adm. Op. to Age/Sex before E. hist. toop. death No. (yr) adm. (d) in stool Preop. diagnosis (d) (d) Extent of necrosis ~~
+
Typhoid
4
-
-
Bacillary dysentery Appendix abscess
2 3
4 14
+ +
Amoebic colitis Amoebic colitis
4 6
-
1
60/F
20
2 3
29/F 71/M
2 10
4 5
44lM 39/F
120 10
6
3/M
6
7
85/M
14
8
58/F
10
9
50/F
5
-
71/M
7
-
2. Amoebic colitis Amoebic colitis
2. 8
10
0
-
11
60/M
14
-
Giardiasis
1. 5 2. 15 3. 17
21
-
-
Bacillary dysentery Bacillary dysentery Peritonitis
1. 7 2. 10 2
0
14
14
5
-
1. Appendix abscess 1. 4
Entire colon
Procedure
Total colectomy, ileostomy and closure of rectal stump Entire colon Caecostomy, drainage Entire colon except Subtotal colectomy, distal sigmoid ileostomy and mucous fistula Entire colorectum Panproctocolectomy Entire colon Total colectomy, ileostomy and mucous fistula Caecum to 1. Caecostomy descending colon 2. Drainage Entire colon Total colectomy, ileostomy and closure of rectal stump Caecum to midRight colectomy transverse colon 1. Caecostomy, ileoCaecum to midtransverse colon transverse bypass 2. Right colectomy Entire colon except Subtotal colectomy, distal sigmoid ileostomy and mucous fistula 1. Drainage 2. Ileostomy Entire colon 3. Total colectomv
631
Result Surv. Died Died Died Surv.
Died Died Surv.
Surv. Surv.
Died
Adm., admission; op., operation; E. hist., Entamoeba histolytica; surv., survived.
inflamed parietal peritoneum. There were areas of full-thickness colliquative necrosis and areas with relatively normal serosa concealing complete mucosal necrosis. Perforations were usually multiple and widely distributed. Many perforations were partially concealed in the inflamed omental envelope and became evident as soon as the colon was touched. In more severe cases long necrotic segments of the colon had completely disintegrated with free spillage of content. The extent of colonic involvement was as shown in Table 1. Conservative surgery, i.e. drainage with external faecal diversion or internal bypass, was performed in 3 patients (Cases 2, 6 and 9) with disastrous consequences. It resulted in rapid deterioration due to spreading colonic necrosis in spite of specific anti-amoebic treatment. One of these patients (Case 2) died within 4 days of the operation from severe toxaemia, 2 patients required re-exploration because of peritonitis and only 1 patient (Case 9) survived after a colonic resection. Conservative surgery was used as a temporary procedure in 1 patient (Case 11) in the hope that the patient might improve sufficiently to allow colonic resection later. There was no improvement and the patient died after colectomy. Resection of the diseased colon with external faecal diversion and abdominal drainage was performed in 7 patients and 4 survived. Mortality Six patients in this series died, giving an overall mortality of 55 per cent. Early postoperative deaths were due to shock and toxaemia while late deaths were due to sepsis. The mortality rate was 75 per cent among those who had conservative surgery such as diversion and drainage as the primary procedure and
43 per cent for those who had resection with exteriorization as the primary procedure. The mortality was related to the extent of colonic necrosis. When the disease was confined to the area proximal to the midtransverse colon the mortality was 33 per cent compared with 57 per cent with more distal colonic involvement and 100 per cent with entire colorectal involvement. Mortality was also related to the preoperative condition of the patients. Among those with a poor preoperative state, as characterized by persistent shock (systolic blood pressure below 100 mmHg), associated cardiopulmonary insufficiency, electrolyte imbalance and hypoproteinaemia with generalized oedema, the mortality was 80 per cent compared with 33 per cent in those in a better preoperative condition. Delay of more than 48 h in the diagnosis of colonic necrosis and peritonitis also resulted in a mortality of 67 per cent, twice as high as in those with an earlier diagnosis (38 per cent). Discussion Fulminating amoebic colitis has been observed in debilitated subjects who are suffering from malnutrition, chronic illnesses and intestinal infections (Adams and Maegraith, 1960). In an area where amoebiasis is endemic, infestation with various intestinal parasites is also rife. The role of these parasites in the pathogenesis of fulminating amoebic colitis is not known. Their association in many of our cases, together with the low socioeconomic background of the patients, is indicative of the poor hygiene and low standard of health of these people. Similar predisposing factors have been observed by others (Palaez et al., 1966). The diagnosis of amoebic colitis normally rests on the typical history of bloody mucous diarrhoea,
632
T. Vajrabukka et al.
proctoscopic or sigmoidoscopic observation of of the colitis must be resisted. Severe amoebic colitis typical amoebic ulcers and, particularly, the demon- may require operation at any stage and anti-amoebic stration of E. histolytica in the stools and mucus. In drugs cannot prevent a necrotic colon from sloughing fulminating amoebic colitis the diagnosis is difficult even if all amoebae have been eradicated (Stein and because of its unusual presentation. The disease runs Bank, 1970; Mukerjee and Nigam, 1975). We agree a fulminating course in most patients, with diarrhoea with Stein and Bank (1970) that persistent diarrhoea, of varying severity. The diagnosis on clinical history abdominal tenderness and severe toxaemia, despite is relatively easy only in the rare event of the disease adequate anti-amoebic therapy, are indicative of severe superimposing upon the chronic form of amoebic colonic necrosis and the need for operation. Our results suggest that there is no place for concolitis. Sigmoidoscopy is difficult because of the almost continuous passage of mucus and because the servative surgery, particularly in undiagnosed or unfriability of the colon makes it hazardous. When treated patients. It has long been known that diversion, performed gently and skilfully without air insufflation, or diversion alone, seems to accentuate the sloughing sigmoidoscopy may provide a diagnosis in a limited of the necrotic colon (Manson-Bahr, 1939). The best number of patients with rectal or sigmoid involve- operative treatment is primary resection of the diseased ment. The curious periodic absence of amoebae in bowel with exteriorization of the ends in all patients the stools further compounds the diagnostic difficulty who are fit for laparotomy. In the past fulminating amoebic colitis always and much valuable time is lost in pursuing alternative diagnoses such as bacillary dysentery, typhoid or even carried a mortality approaching 100 per cent, whatidiopathic ulcerative colitis, which is very rare in ever the form of operative treatment (Hawe, 1945; Thailand. By the time amoebiasis is confirmed it is Rives et al., 1955; Palaez et al., 1966; Chen et al., often too late to commence effective anti-amoebic 1971 ; Sharma et al., 1975). This was due to the poor therapy. We feel that in an area where amoebiasis is preoperative state as a result of delay or inadequate endemic a trial of anti-amoebic therapy is worth while surgical treatment or both. The overall mortality in in patients with severe, undiagnosed colitis. In such this series is 55 per cent and indicates that fulminating instances the diagnosis must depend first upon the amoebic colitis is not inevitably fatal. It is our contentherapeutic response and later on the result of specific tion that we can reduce the mortality further by serological tests. Prompt anti-amoebic therapy may employing a high degree of suspicion, prompt antiarrest the progress towards irreversible colonic amoebic therapy, careful clinical evaluation and, if necrosis in some patients and in others may improve there is not rapid improvement, adequate resectional the prognosis should surgery become necessary. The surgery. cardiac toxicity of emetine makes it unsuitable in many patients who are already hypotensive from References toxaemia; metronidazole is much safer and equally ADAMS A. R. D. and MAEGRAITH B. G. (1960) Clinical Topical Diseases, 2nd ed. Oxford, Blackwell Scientific, p. 8. effective. The detection of colonic necrosis without perfora- CHEN w. J., CHEN K. M.and LIN M. (1971) Colon perforation in Arch. Surg. 103, 676-680. tion is difficult in fulminating amoebic colitis because HAWEamoebiasis. P. (1945) The surgical aspect of intestinal amoebiasis. its development is insidious and is usually masked by Surg. Gynecol. Obstet. 81, 387-404. severe preexisting local signs and toxaemia. Mucous MANSON-BAHR P. H. (1939) The Dysenteric Disorders. London, diarrhoea often continues in the presence of colonic Cassell. necrosis and peritonitis. By the time perforation is MUKERJEE s. and NIGAM N. (1975) Amoebic perforation of the colon. Am. J. Proct. 26, 57-63. recognized from the X-ray evidence of free air under the diaphragm the patients are usually very ill from PALAEZ M., VILLAZON A. and ZARABOSO R. s. (1966) Amoebic perforation of the colon. Dis. Colon Rectum 9, 356-362. toxaemia, making operation hazardous. Clearly every J. D., HEIBNER w. c. and POWELL J. L. (1955) The surgical effort must be made to detect the stage of irreversible RIVEScomplications of amoebiasis of the colon. Surg. Clin. colonic necrosis and to operate before the patient’s North Am. 35, 1421-1426. condition becomes precarious. This requires an SHARMA B. D . , CHOORAMANI s. and AGARWAL A. K. (1975) Acute awareness of the diagnosis and vigilant monitoring of amoebic necrosis of bowel. Am. J. Proct. 26, 57-62. the vital signs, abdominal girth, tenderness, severity STEIN D. and BANK s. (1970) Surgery in amoebic colitis. Gut 11, 941-946. of diarrhoea and frequent abdominal X-rays to detect dilated featureless coIon (toxic megacolon). False optimism on the confirmation of the amoebic nature Paper accepted 19 April 1979.
