Gut, 1990,31,439-442

Schistosomal colonic disease

Abdel Rahman El-Shiekh Mohamed, Mohamed Ali Al Karawi, Mohamed Ismail Yasawy

AbstractThis study evaluates 216 patients with schisto-somal colonic disease, diagnosed by endo-scopic biopsies at the Armed Forces Hospital,Riyadh. The colonoscopic appearance was

suggestive of schistosomiasis in 98 of thesepatients (45.37%), Schistosoma mansoni ova instool was detected in only 24 of these 216patients (11-11%). The most common histo-pathological finding in colonic biopsies ofthese patients was Schistosoma mansoni ova inthe colonic mucosa with no or mild inflam-matory celis infiltrates. These findings corre-late with the endoscopic appearances in mostpatients. The most common symptoms were

abdominal pain or distention in 84 patients(38.88%). Sixty five patients (30.09%) hadhepatosplenic schistosomiasis. Eight patientshad schistosomal polyps and two patients hadcolonic malignancy in which no associationbetween their malignancy and Schistosomamansoni infection was established. After anti-schistosomal treatment follow up, sigmoidos-copy was normal in 28 patients who previouslyhad abnormal endoscopic appearances.Colonoscopic examination is valuable incolonic schistosomiasis as it can show charac-teristic colonic lesions and colonic biopsies are

diagnostic and correlates with histologicalfindings.

tation and complications of schistosomal colonicdisease.

Methods

PATIENTSBetween March 1979 and December 1988, 2710patients with different gastrointestinal tractproblems had fibreoptic sigmoidoscopy (1911patients) or colonoscopy (799 patients) examina-tion at the Gastroenterology Unit, Armed ForcesHospital, Riyadh, Kingdom of Saudi Arabia.Three to six colonic biopsies (0 1-0 6 cm) were

taken from each patient with a visible lesionduring examination, for histological examinationby paraffin section. Two extra rectal biopsieswere taken for crush biopsy (squash technique)6in patients suspected of schistosomiasis even ifthe colonic mucosa looked normal. This tech-nique began to be used in those patients endos-coped since the beginning of 1986. Snare poly-pectomy was done in patients with polyps. Ineach patient suspected of schistosomiasis atleast three stool specimens were examined forova by the Formal ether concentrationmethod.7 All patients received antischistosomaldrugs. Three to six six months after treatmentfollow up sigmoidoscopy was done in 28patients.

GastroenterologyDivision, Armed ForcesHospital, Riyadh,Kingdom of Saudi ArabiaAbdel Rahman El-ShiekhMohamedMohamed Ali Al KarawiMohamed Ismail YasawyCorrespondence to: Dr A EMohamed (C149), ArmedForces Hospital, PO Box 7897,Riyadh 11159, Kingdom ofSaudi Arabia.Accepted for publication19 June 1989

Schistosomiasis is a serious endemic disease intropics and subtropics. It affects child develop-ment and adult productivity. Over 200 millionpeople in the world suffer from schistosomiasisand several other million are exposed to theinfection.' Two species of schistosomes com-

monly produce intestinal disease: Schistosomamansoni and japonicum and rarely haematobiumand intercalatum. Schistosoma mansoni is endemicin Africa, South America, and the Middle Eastincluding Saudi Arabia.2 In the large intestine,viable ova produce an inflammatory reaction,granuloma formation, papillomatae, ulceration,bleeding, subsequently fibrosis which give rise tothe longterm sequelae of the disease.3 Acuteschistosomiasis4 and schistosomal intestinaldisease cause usually diarrhoea with blood andmucus. Exacerbations occur every few weeks.The passage ofthe ova in stool is frequent in earlystages but later when the disease becomeschronic, the ova passage in stool is infrequentand scanty.5 There are few studies on schisto-somal colonic disease and there is paucity in theliterature on schistosomal colonoscopic appear-ances and the value of colonic biopsies in makinga diagnosis.The aim of this study is to discuss the colonos-

copic appearances, histological findings and thevalue of colonic biopsies in diagnosing Schisto-soma mansoni infection. It also discusses presen-

ResultsColonic biopsies for histological examinationwere taken in 2458 patients from all patients whohad sigmoidoscopy or colonoscopy. In 1820 ofthese patients it showed normal colonic mucosaand an abnormality was reported in the remain-ing 638 patients (Table I). The most commonpathological finding was Schistosoma mansoni in216 patients (200 men and 16 women). Theirages ranged from 11-72 years (mean 36 8). Eightpatients had schistosomal polyps. The histologi-cal findings are shown in Table II and Figure 1.The endoscopic appearance in these patients areshown in Table III and Figure 2. Sixty eightother patients had adenomatous polyps and 32had rectal or colonic malignancy, in two ofwhichSchistosoma mansoni ova was also seen in theircolonic biopsies (one patient with adenocar-cinoma of rectum and another renal transplant

TABLE I Abnormal colonic biopsyfindings in 638 patients

Colonic biopsvfindings Patients (n)

Schistosoma mansont 216Schistosomal polyp 8Adenomatous polyp 68Adenocarcinoma colon 18Adenocarcinoma rectum 8Other malignant lesions 6Other specific infection and inflammatory lesions 78Non-specific colitis or proctitis and others 236

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TABLE II Histopathologyfindings in 216 patients with colonic schistosomiasis

Number ofpatients and colonic layer involved

Lamina Muscularis Patients:Range ofinflammatory reaction Mucosa Propria Submucosa Mucosa Total n

Schistosoma ova with no or mild reaction 53 11 9 2 75Schistosoma ova with moderate reaction 20 22 6 2 50Schistosoma ova with severe reaction 13 0 0 0 13Schistosoma ova with eosinophillic

infiltration only 4 0 0 0 4Schistosoma ova with granuloma 39 7 7 2 55Schistosoma ova with polyp 8 0 0 0 8Normal histology positive crush biopsy 11 0 0 0 11Total 148 40 22 6 216

patient with Kaposi sarcoma). Detailed histo-logical examinations of the colonic biopsies inthese two patients showed no associationbetween their malignancy and Schistosomamansoni. Crush biopsy technique (Fig 3) wasdone in 49 patients, in whom it showed manySchistosoma mansoni ova with characteristiclateral spine. In 11 of these patients, the paraffinsections did not show Schistosoma mansoni ova.The colonoscopic appearance in these 11 patientswas normal. In 64 other patients with normalcolonoscopic appearance the histopathogicalfindings showed the presence of schistosoma ovawith no or minimal inflammatory cell reaction.In four patients the ova shell was empty with nomiracidium seen inside, indicating dead ova. In22 patients with very little ulceration seenduring endoscopic procedure, the histopatho-logical findings showed the presence of ova withmoderate to severe inflammatory cell reactioninfilteration. Stool examination showedSchistosoma mansoni ova in ony 24 (11I11%) ofthese 216 patients.The most common symptoms in the 216

patients with schistosomal colonic disease areshown in Table IV. Sixty five of these patientshad hepatosplenic schistosomiasis. Table Vshows the clinical impression on referral forendoscopy. After treatment 103 patients becameasymptomatic, 54 patients improved while theremaining 59 patients had no significantimprovement as most of these patients hadhepatosplenic schistosomiasis.

TABLE III Endoscopicfindings in 216 patients with colonicschistosomiasts

RectumEndoscopic appearance Rectum Colon +colon Total

Patchy mucosal congestion+petechiae 24 11 26 61

Patchy erosions+ulcerations 9 3 10 22Telangiectasis 1 2 4 7Polyps 3 5 8Normal 118 118Total 37 21 158 216

After treatment follow up sigmoidoscopy wasperformed in 28 out of the 98 patients who hadabnormal endoscopic appearances. In all 28patients the endoscopic appearances becamenormal and colonic biopsies for schistosomiasisalso became negative.

DiscussionSchistosomal colonic disease is a major healthproblem in endemic areas and if not diagnosedand treated early might lead to complicationssuch as chronic intestinal schistosomiasis andhepatosplenic schistosomiasis, which have highmorbidity and mortality.The symptoms of colonic schistosomiasis are

Figure 2: Endoscopic views, showing erosions and tinyulcerations in rectal mucosa as a result ofschistosomiasis(above) and colonic schistosomal polyp (below).

Figure 1: Colonic mucosa showing three Schistosoma mansoni ova, surrounded bygranuloma. Lateral spine is clearly shown in the ova in the right side.

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Schistosomal colonic disease

Figure 3: Many Schistosoma mansoni ova seen in rectal mucosa (squash or crush biopsytechnique).

non-specific and may mimic several other gastro-intestinal problems, as shown in Tables IV andV. Therefore an early diagnosis in schisto-somiasis is important as in its early stage it is atreatable condition. The new antischistosomaldrugs (praziquantel or oxamniquine) are safe andeffective in halting the progress of the disease.'The diagnosis of acute intestinal schistosomiasisis usually established by finding ova in the stooland this forms no diagnostic problem for theclinician working in endemic areas. The diag-nosis of chronic intestinal or hepatosplenicschistosomiasis is not simple, however, as in thiscondition the passage ofova in stool is infrequentand scanty.5 As shown in this study, stool exam-ination might be negative, while rectal or colonicbiopsies are positive. This was also shown byShoebt who used rectal biopsy transparencytechnique and was positive in revealing ova in78% of his patients and found to be superior tostool and rectal swab or curette, in diagnosingSchistosoma mansoni.

In this study the squash technique was foundto be simple and rapid in showing many charac-teristic schistosoma ova compared with histo-logical examination by paraffin section. Fibre-optic sigmoidoscopy or colonoscopy may showclearly the colonic lesions as shown in ourpatients and even in the 118 patients whose

TABLE IV Symptoms in 216 patients

Symptoms Patients (n)

Non-specific abdominal pain 84Diarrhoea 58Bleeding per rectum 43Alternate diarrhoea and constipation 22Constipation 9

TABLE V Clinical impression in 216 patients beforeendoscopy

Assessment Patients (n)

Schistosomiasis 93Schistosomal portal hypertension 15Irritable bowel syndrome 66Inflammatory bowel disease 16Malignancy 8Infective diarrhoea 9Others 9

colonic mucosa looked normal, biopsies showedschistosoma ova. This study also showed that thehistological findings can be correlated with theendoscopic findings. From 63 patients whosecolonic biopsies showed moderate to severeinflammatory reaction, 22 had very little ulcera-tion shown endoscopically and possibly thesepatients had active disease, while from 75patients with minimal or no reaction, 71 hadnormal endoscopic appearances and these hadquiescent or chronic disease as most of the latterpatients had hepatosplenic form. This might alsoexplain why in chronic schistosomiasis, thepresence of ova in stool is usually infrequent andscanty.Endoscopy is not only diagnostic in patients

with schistosomal polyps but in this conditionthe polyp could be endoscopically excised com-pletely.9 Severe rectal bleeding or intussuscep-tion can result due to bilharzial polyps.'As shown in this study and previous studies'0

that sigmoidoscopy or colonoscopy is an impor-tant diagnostic tool in schistosomal colonicdisease. Few patients may present withabdominal mass because of pericolic or mesen-teric granuloma and may present with intestinalobstruction. In our hospital during the last threeyears, three patients presented with intestinalobstruction, two other patients had mesentericvein involvement and three others presentedwith acute appendicitis (Figure IV) and all hadsurgery which proved to be caused by compli-cated intestinal schistosomiasis. These colonicmasses, if not investigated properly may bemisdiagnosed as carcinoma, lymphoma orCrohn's disease.'2 Colonic malignancy was theclinical impression before referral for endoscopyin eight of our patients.The development of carcinomatous changes in

Schistosoma mansoni colonic disease or polyps isnot established and such association has only sofar been linked with Schistosoma japonicum. Chaiet al from China studied 454 colorectal carcinomaspecimens of which 289 were associated withSchistosoma japonicum infestation and who haddiffuse involvement of the large intestine and ahistory of 10 years or more of colitic symptoms.'3There are no definite reports, however, on theassociation between colorectal cancer andSchistosoma mansoni.3 Dimmettee et al studied 98Egyptian patients with carcinoma of the largebowel and 17 of these had Schistosoma mansoniinfestation in which detailed histological studiesrevealed no outstanding features to distinguishparasitic from non-parasitic groups. 14 This histo-logical finding was also established in two of ourpatients.

In our study only 26 patients (0-96%) hadadenocarcinocarcinoma of the colon or rectum,which is a low incidence compared with studiespublished from the West" and Far East.'6 Asschistosomiasis is endemic in Saudi Arabia and ifSchistosoma mansoni plays an aetiological role incolonic malignancy, it would have been expectedthat the incidence of colorectal cancer to behigher in areas where Schistosoma mansoni isendemic.

Embolisation of ova to the liver leads tohepatosplenic schistosomiasis which is a majorcomplication of intestinal schistosomiasis, and

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442 Mohamed, Karawi, Yasawy

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Figure 4: High powerfield showing schistosoma granulomas in an appendicectomy specimen ofa patient who presented with acute appendicitis.

bleeding from the resultant oesophageal orgastric varices is a major cause of death. In ourunit, 50 patients with hepatosplenic schisto-somiasis received sclerotherapy for bleedingoesophageal varices and this was found to beeffective in stopping acute bleeding in thesepatients."7 The diagnosis in hepatosplenicschistosomiasis is based on visualisation of ova instool, rectal biopsy or liver biopsy, but the lattermight not be possibly caused by coagulopathy.The demonstration of periportal brightness andincreased echogenicity in liver ultrasound is alsohelpful in suggesting the diagnosis. "

This study has shown that in colonic schisto-somiasis there are characteristic colonoscopicappearances related to the stage of the diseaseand these can be correlated well with the histo-pathological findings. These abnormal endos-copic findings disappeared in 28 patients after

treatment. It also shows that the colonoscopicbiopsies are superior to stool examination infinding Schistosoma mansoni ova. Also it showsthat Schistosoma mansoni infestation does notusually predispose to colorectal malignancy.

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