An 11-year-old boy with chronic diarrhea and weight loss

Dr. Maimuna Sayeed: An 11-year-old boy presented with 15 months history of diarrhea with up to 10-20 times small volume stool daily with mucus. It was associated with a feeling of incomplete defecation and excessive straining. The frequency of diarrhea increased to 20-30 times per day over the last 8 months. Subsequently, he developed fecal incontinence, for which he couldn't attend his school. He also had a history of significant weight loss in the last 7 months. According to his mother's statement, his body weight was reduced to 64 kg from 77 kg during this illness. In spite of receiving several antibiotics and antidiarrheal medications prescribed by a registered physiccian, his symptoms had not resolved. He had no history of constipation, self-digitation, per rectal bleeding, fever, anal or abdominal pain, oral ulcer, skin lesion, joint pain, TB contact, and no significant family history. There was no evidence of any significant visible rectal prolapse. During his course of illness, he was symptom-free for 4 months irrespective of any treatment.

The findings of the physical examination were unremarkable. He was mildly pale, afebrile, not dehydrated, skin survey was normal, BCG mark was present, lymph nodes not enlarged and vitally stable. His anthropometric measurements were at 97 th percentile for weight (59 kg), at 95 th to 97 th percentile for height and body mass index for age at 95 th to 97 th percentile. The abdomen was soft and non-tender with no organomegaly or ascites, bowel sound was present. Perianal findings and digital rectal examinations were unremarkable. Other systemic examinations revealed no abnormality.
X-ray chest and abdomen were normal ( Figure  1).
Stool examination was done repeatedly for ova, parasite and culture was found negative (Table  I).
Prof. Md. Rukunuzzaman: Colonoscopy findings revealed rectal mucosal nodularity and ulceration. (Figure 2). The mucosa and vascular pattern of the rest of the colon appeared to be normal. Multiple biopsies were taken from the lesions.
Dr. Bishnu Pada Dey: Histopathological examination revealed moderate infiltration of chronic inflammatory cells in the lamina propria and surface erosion. The crypts were diamondshaped. The muscularis mucosa was thick and thin bands of smooth muscle fibers were present in between the crypts. No granuloma or malignancy was seen ( Figure 3). The diagnosis was compatible with the solitary rectal ulcer.

Provisional Diagnosis
Solitary rectal ulcer syndrome

Differential Diagnosis
Dr. Luthfun Nahar: As the patient presented with chronic diarrhea and significant weight loss, the duration is long and also as Bangladesh is a highly endemic zone for the tuberculosis, so after considering these facts and evaluating the other features, it could be a case of intestinal tuberculosis.

Intestinal tuberculosis
Chronic diarrhea in children is one of the most common clinical presentations of intestinal tuberculosis. Malnutrition, overcrowding, poverty and HIV co-infection aid the spread of tuberculosis. 1 Mycobacterium tuberculosis and M. bovis are the principal cause of intestinal tuberculosis. Tuberculous bacilli can infect the gastrointestinal tract by the following route: a) hematogenous spread from primary lung focus; b) ingestion of bacilli from the infected sputum; c) unpasteurized cow's milk ingestion; d) lymphatic spread from the adjacent lymph nodes and e) direct spread from an adjacent organ. The most common site of involvement of intestinal tuberculosis is the ileocaecal region. 2 There are 3 forms of intestinal tuberculosis: ulcerative, hypertrophic or ulcerohypertrophic or fibrous structuring form. 3 The patient may present with the fever, night sweats, weight loss, altered bowel habit, abdominal pain, and occasional right iliac fossa mass. Diarrhea in the intestinal tuberculosis results from the intestinal mucosal ulceration. 4 This patient presented with chronic diarrhea and significant weight loss which are suggestive of intestinal tuberculosis, but no history of fever, abdominal pain, cow's milk ingestion, no contact history with tuberculosis patient, and no lymphadenopathy go against the intestinal tuberculosis.
The final diagnosis is based on the clinical features, culture and polymerase chain reaction (PCR) for M. tuberculosis, tuberculin sensitivity test, radiological investigations (plain and contrast X-ray of the barium meal, follow-through, enema) colonoscopic and histopathological findings. Plain X-ray of the abdomen may show signs of obstruction (presence of multiple air-fluid levels and dilated bowel loops) and/or feature of perforation (air under diaphragm) and calcified abdominal lymph nodes. Contrast studies help to demonstrate the intestinal mucosal pathology. The histopathological hallmarks of tuberculosis are confluent, caseating granulomas having acid-fast bacilli surrounded by lymphoid tissue. In this patient tuberculin sensitivity test was negative, plain X-ray of the abdomen was normal, colonoscopy showed no involvement in the ileocaecal region and histopathology showed no caseating granuloma.

Inflammatory bowel disease
Dr. Bodhrun Naher: Chronic diarrhea is a common presenting feature of inflammatory bowel disease. Other features are weight loss, abdominal pain and per rectal bleeding. It is a chronic inflammatory disease of the gastrointestinal tract. It occurs as a result of dysregulation of the mucosal immune response against the commensal intestinal microbiota due to multiple factors like genetic, environmental and the microbiome. 5 It has two main subtypes, ulcerative colitis and Crohn's disease. Ulcerative colitis is diffuse, continuous inflammation of the colon extending from the rectum proximally. Crohn's disease can involve any part in the gastrointestinal system from the mouth to the anus but most commonly involves the terminal ileum and colon can present with skip lesions. The presentation of inflammatory bowel disease in children can be variable. 6 Besides the classical features, children may also present with growth failure, anemia, perianal disease, or other extraintestinal manifestations. 7 In case of this patient, there was only features of chronic diarrhea and weight loss.
Laboratory findings in children with inflammatory bowel disease show anemia, thrombocytosis, hypoalbuminemia, and elevated levels of inflammatory markers like ESR and C-reactive protein. 8 Stool needs to be examined for the occult blood, bacterial pathogens (including Clostridium difficile), ova, and parasites and fecal calprotectin. Imaging studies

A B
including plain and contrast X-ray, endoscopy of the upper and lower gastrointestinal tract with histopathology play important roles in establishing the diagnosis. The plain X-ray abdomen may show distended bowel loop, thumb printing sign and loss of haustration. The contrast X-ray shows pathology in the gastrointestinal tract. A colonoscopy reveals aphthous ulcer, linear ulcer, a cobblestone appearance, fistula, stricture and diffuse superficial ulceration of colon. Histological hallmarks of Crohn's disease are intramural and submucosal involvement and presence of non-caseating granuloma. In case of ulcerative colitis, inflammation limited to the mucosa, crypt abscess, cryptitis, and depletion of goblet cells may be present. In this case, none of the findings was present.

Discussion
Prof. Rukunuzzaman: The solitary rectal ulcer syndrome is an uncommon, benign and chronic disease of the rectum. It affects predominantly adults and rare in children. 9 Its incidence was at 1 in 100,000 per year. Men and women are equally affected but there is a small predominance in women. 10 The condition was first reported by Cruveilhier in 1830, the term solitary rectal ulcer syndrome was first used by Dr. Lloyd-Davis in the 1930s. Thereafter, its clinical and histopathological features were described by Dr. Madigan in 1969. 11, 12 Solitary rectal ulcer syndrome is sometimes diag-  Patients typically present with per rectal bleeding, tenesmus, copious mucous discharge, prolong excessive straining, perianal and abdominal pain, feeling of incomplete defecation, constipation, and rarely rectal prolapse. 20- 22 The amount of blood loss varies from a small amount of fresh blood to severe hemorrhage that may require a blood transfusion. 23 Often children may present with apparent diarrhea (because of prolonged visits to the toilet), pain, tenesmus, weight loss, suggest to clinicians that the presence of inflammatory bowel disease. 24 The complaints of diarrhea arose due to frequent passage of mucus. Patients with solitary rectal ulcer syndrome attempt to defecate about 10-11 times per day and about half of them experience toilet visit lasting more than 15 min. 25 It is unusual and a child may present with recurrent per rectal bleeding and severe anemia requiring a blood transfusion. 26 Up to 26% of patients can remain asymptomatic and diagnosed incidentally while investigating other diseases. 13 The diagnosis of solitary rectal ulcer syndrome is based on the clinical features, proctosigmoidoscopy findings, and histopathological examination. 27 A thorough and complete history are the most important in the initial diagnosis. The differential diagnosis includes intestinal tuberculosis, inflammatory bowel disease, ischemic colitis and malignancy. Per rectal bleeding may be misinterpreted as a case of anal fissure caused by constipation or as other cause of per rectal bleeding such as a juvenile colonic polyp. 16,28 Colonoscopy and biopsy should be performed from normal and abnormal-looking rectal and colonic mucosa. 22 The ulcer is commonly located on the anterior wall of the rectum and the distance of the ulcer varies from 3 to 10 cm from the anal margin. 11 The diameter of the ulcer ranges from 0.5 to 4 cm but usually 1-1.5 cm. 13 Appearance of the ulcer may vary from per ulcer that covered by a white, grey or yellowish slough. 11, 13 The lesion may appear as shallow ulcer and the adjacent mucous membrane may appear nodular, granular or lumpy. 29 The polypoid lesion may found in 25% cases of solitary rectal ulcer syndrome, patchy mucosal erythema may appear in 18% cases and multiple lesions may found in 30% cases. 22 As a result of the wide range of macroscopic findings of solitary rectal ulcer syndrome, the condition may go unrecognized or misdiagnosed, so it is important to collect biopsy specimen from the lesion site to confirm the diagnosis and to exclude the differentials. 10 Dr. Dey: Histological features of solitary rectal ulcer syndrome are superficial ulcer, mild inflammation, fibromuscular obliteration of lamina propria, muscularis mucosa is hypertrophied having thick and thin bands of smooth muscle with an extension of muscle fibers upwards between the crypts. The crypts are hyperplastic elongated along with some diamond-shaped crypts and crypt glandular abnormalities. 30 Dr. Khan Lamia Nahid: Some imaging investigations can help in the diagnosis of solitary rectal ulcer syndrome including defecating proctography, dynamic magnetic resonance imaging and anorectal functional studies that are manometry and electromyography. 27 Defecography, useful in determining the presence of intussusception or mucosal prolapse, can identify a hidden prolapse, non-relaxing puborectalis muscle, delayed or incomplete rectal emptying. 31 Defecography is usually reserved possibly for preoperative assessment. 32 Barium enema shows thickened rectal folds, rectal stricture, and ulceration, polypoid lesion, the granularity of the mucosa but all of these are nonspecific findings. 33 Anorectal manometry and electromyography give important information about the anorectal inhibitory reflex, defecation dynamics, pressure profile, rectal compliance, and sensory thresholds. 22 Some studies have shown the usefulness of anorectal ultrasound in assessing the thickness of internal anal sphincter which is increased in solitary rectal ulcer syndrome. 34 The thick internal anal sphincter is highly predictive of high-grade rectal prolapse and rectal intussusception. 35 Routine laboratory tests like hemoglobin, red blood cell counts, white blood cell counts, platelet counts, erythrocyte sedimentation rate, C-reactive protein, liver function tests and coagulation profile are usually normal. In a child with a history of recurrent per rectal bleeding may have the feature of microcytic anemia. 27 Prof. Rukunuzzaman: The choice of treatment option depends on the severity of the symptoms and the presence of rectal prolapse. The option for solitary rectal ulcer syndrome includes conservative treatment (ie, diet and bulk laxatives), medical therapy, biofeedback, and surgery. The first step of treatment is the patient education and behavioral modification. 36 In asymptomatic case, the patient may not need any treatment except behavioral modification. Patient should be counseled and reassured that the lesion is benign, high fiber diet should be encouraged, advised to avoid straining, regulation of toilet habit and to discuss any psychosocial factors. 37 In mild to moderate cases with absence of mucosal prolapse, patients may be treated with conservative treatments. Behavioral modification and dietary advice are effective enough. The patient may be treated with bulk laxatives, bowel retraining, and reassurance. 38 The training for prevention of straining and digitation, dietary and behavioral changes should be given.
In the presence of rectal prolapse, high degree of intussusception in rectum and fibrosis, conservative treatment may not be effective and resistance may develop to this therapy. Biofeedback can help in improving symptoms in these patients. Biofeedback includes behavioral changes that are effective in reducing excessive straining during defecation through correction of abnormal pelvic floor behavior and stopping the use of laxatives and suppositories. 16

Final Diagnosis
Solitary rectal ulcer syndrome