7 Contemporary radiological examination of the upper gastrointestinal tract

Barium and endoscopy both have advantages. Endoscopy not only gives you direct visualization but also the ability to biopsy tissue. It does not give you the ability to determine the exact anatomy or the gross appearance of a lesion. Barium on the other hand gives you a dynamic examination which is particularly useful for the assessment of swallowing disorders and oesophageal motility. When the pharynx and oesophagus are not of prime concern and cost is not a problem then endoscopy is the examination of choice. It has been shown that dyspeptic patients who have had both examinations have a definite preference for endoscopy (Stevenson et al, 1991). As endoscopy requires minimal physical effort, it is also a preferable examination for the unwell patient.     

Mucin histochemistry of the lower gastrointestinal tract

Variations in the mucin secretion pattern in the mucosal lining of the colon and rectum have been studied. Mucins have been differentiated histochemically as neutral mucins, sialomucins and sulphomucins, using alcian blue/PAS and HID/alcian blue techniques. In the normal colonic mucosa, the goblet cells secrete predominantly sulphomucins with small amounts of sialomucins. Twenty one cases with benign lesions showed varying patterns of mucin secretion. In the 35 cases with adenocarcinoma studied, the transitional mucosa adjacent to the lesion showed a reversal of mucin secretion pattern, with an increase in sialomucins and a marked decrease in sulphomucins, suggesting a reaction to neoplasia.     

Management of lower gastrointestinal tract bleeding

Acute bleeding from the colon and rectum is less frequent and less dramatic than haemorrhage from the upper gastrointestinal tract. In most cases, bleeding from the colon and rectum is self-limiting and requires no specific therapy. Diverticula and angiectasias are the most frequent sources of bleeding. Malignancy, colitis (inflammatory bowel disease, non-steroidal anti-inflammatory drugs, and infectious colitis), ischaemia, anorectal disorders, postpolypectomy bleeding, and HIV-related problems are less frequent causes. The recurrence rate, especially in diverticular bleeding, is high. Resuscitation and haemodynamic stabilisation of the patient is the first step in the management of colonic bleeding. Urgent colonoscopy is the method of choice for diagnosis and therapy. By analogy with peptic ulcer bleeding, risk stratification using stigmata of haemorrhage is gaining more importance. Modern endoscopic techniques such as injection therapy, thermocoagulation and mechanical devices seem to be effective in achieving haemostasis and avoiding precarious surgery. Angiography and nuclear scintigraphy are reserved for those patients in whom colonoscopy is not possible or has repeatedly failed to localise the bleeding site.     

Endoscopic clipping in the lower gastrointestinal tract

Endoscopic clipping has been established as a safe and effective method for the treatment of nonvariceal upper gastrointestinal bleeding in numerous randomized studies. Recently, clipping has been applied to various lesions in the lower gastrointestinal tract, including diverticular bleeding, postpolypectomy bleeding, and repair of perforations with successful outcomes. We review the safety and efficacy of this maneuver for the management of diseases in the lower gastrointestinal tract.     

Endoscopic examination of the upper gastrointestinal tract in infancy

Forty endoscopic examinations of the upper gastrointestinal tract were performed in 38 infants with an age range from 2 days to 12 months. The main indications were upper gastrointestinal bleeding, chronic intractable vomiting, and small intestinal biopsy. Duodenal ulcer, hemorrhagic gastritis, and gastric erosions were the most common causes of upper gastrointestinal bleeding in infancy. An acute viral infection with fever, aspirin ingestion, and diarrhea frequently preceded gastrointestinal bleeding from duodenal ulcer and gastric erosion. Four of the 27 bleeding patients demonstrated no abnormality endoscopically.     

Long-term follow-up of patients with iron deficiency anemia after a close endoscopic examination of the upper and lower gastrointestinal tract

BACKGROUND: In patients with Iron Deficiency Anemia (IDA) occult gastrointestinal bleeding is generally investigated by bidirectional endoscopy. The aim of our study was to examine the long-term follow-up of patients with IDA where the sources of bleeding couldn't be detected despite close endoscopic and radiologic examination of the GI tract. METHODS: Based on the endoscopic data base we examined consecutive patients who were referred for gastrointestinal endoscopy due to IDA with a negative endoscopic (upper GI endoscopy and colonoscopy) evaluation. Further diagnostic work up (repeated endoscopy of the upper and lower GI tract by an experienced investigator, small bowel enteroclysis, push enteroscopy, proctoscopy, intraoperative enteroscopy, angiography, scintigraphic examinations) was recorded. The eligible patients were divided into 2 groups: Group 1 (no identification of the source of bleeding in the GI tract); group 2 (source of gastrointestinal blood loss was found). Long-term follow-up was performed by telephone interview with patients and/or with their general practitioner. RESULTS: 79 patients (mean age 58.8 years [17-83, 44] female) with IDA met the inclusion criteria. In 42 patients (53%) the endoscopic and radiographic evaluation was unable to find the source of gastrointestinal blood loss. 29 of these patients (69%) showed a resolved anemia after a mean follow-up of 48 months (18 months-5 years). 10 patients had a mild anemia, 3 required blood transfusions. In group one Helicobacter pylori infection was significantly more prevalent in comparison with group 2 (57% vs. 38%, p = 0.032). CONCLUSION: Based on our data, the prognosis of IDA with negative endoscopy is favorable. The pathogenic role of Helicobacter pylori infection should be evaluated in further studies.     

Analysis of urgent colonoscopy for lower gastrointestinal tract bleeding

BACKGROUND: Three hundred and forty-five patients who underwent urgent colonoscopy for acute hematochezia during the past 20 years (from 1976 to 1995) were retrospectively analyzed. METHODS: Urgent colonoscopy was defined as endoscopy performed within 24 h after a bleeding episode. Preparation was initially minimal with a water or glycerine enema. Recently, however, polyethylene glycol is used. RESULTS: The overall diagnostic accuracy for bleeding site detection was 89.1% (307 cases). Successful insertion was made to the ileocecal region in 193 cases (55.9%). The disease most frequently discoverd by urgent colonoscopy was transient ischemic colitis (62 cases). Negative urgent colonoscopy specimens (18 cases) were later diagnosed by other methods as being small intestinal bleeding foci. In 10 cases, initial colonoscopy failed to detect the bleeding foci. Endoscopic hemostasis was performed in 48 cases. Permanent hemostasis succeeded in 32 cases (66.7%). Complications of urgent colonoscopy were fever after the examination (22 cases) and hypotension during endoscopy (7 cases). CONCLUSION: Urgent colonoscopy is considered to be a safe and useful examination for acute lower gastrointestinal bleeding and hemostasis.     

Impact of Klebsiella pneumoniae in lower gastrointestinal tract diseases

The 2016 Global Burden of Disease report by WHO revealed that diseases of the gastrointestinal tract (GIT) had one of the highest incidence rates worldwide. The plethora of factors that contribute to the development of GIT‐related illnesses can be divided into genetic, environmental and lifestyle factors. Apart from that, the role that infectious agents play in the development of GIT diseases has piqued the interest of researchers worldwide. The human gut harbors approximately 10¹⁴ bacteria in it with increasing concentration toward the lower GIT. Among the various microbiota that colonize the human gut, Gram‐negative bacteria have been most notoriously linked to GIT‐related diseases such as inflammatory bowel disease (IBD) including Crohn's disease and ulcerative colitis and colorectal cancer (CRC). Some of the notable culprits that have been attributed to these diseases are Bacteroides fragilis, Fusobacterium nucleatum, Escherichia coli and Helicobacter pylori. However, studies in recent years are beginning to recognize a new player, Klebsiella pneumoniae (K. pneumoniae) in the causation and progression of GIT diseases. Once synonymous with infections and diseases of the upper respiratory tract, K. pneumoniae has now emerged as one of the pathogens commonly isolated from patients with GIT diseases. However, extensive studies attributing K. pneumoniae to GIT diseases, particularly that of CRC are scanty. Therefore, this review intends to shed light on the association of K. pneumoniae in gastrointestinal diseases such as Crohn's disease, ulcerative colitis as well as CRC.     

放大内镜检查在消化道疾病中的诊断价值

目前消化道肿瘤的发病率，尤其是结肠肿瘤的发病率日趋增加，然而消化道肿瘤的早期往往无症状。如何发现微小早期病变，特别是如何提高早期癌、微小癌的检出率，需要内镜诊断技术的不断发展。最近高像素和高分辨率放大内镜的问世，可以达到活体解剖显微镜和光学显微镜的效果；结合染色法应用，能够更清晰地观察到黏膜的微细结构，为早期癌、微小癌的发现以及鉴别良、恶性病变提供帮助。     

Polyethylene glycol as a non-absorbable prokinetic agent in the lower gastrointestinal tract

In the rabbit isolated colon, intraluminal infusion of polyethylene glycol facilitates peristaltic activity. The primary target of polyethylene glycol appears to be the intrinsic sensory neurons, and not the excitatory motor neurons. It would appear that polyethylene glycol activates the excitatory pathways of the peristaltic reflex releasing tachykinins and acetylcholine at the level of the intrinsic sensory neurons.