The gastrointestinal system
C. Simon Herrington in Muir's Textbook of Pathology, 2020
This usually affects the terminal ileum. The primary infection – usually caused by drinking milk infected by bovine tuberculosis (TB) – is now rarely seen in the UK following the pasteurization of milk supplies. The condition results in a trivial lesion in the ileal mucosa associated with enlarged, caseating mesenteric nodes. Secondary TB is the result of swallowing infected sputum in the presence of severe pulmonary TB. This results in deep transverse ileal ulcers, which heal by scarring and cause strictures. Sometimes the disease can involve the ileocaecal valve and cause a picture that is macroscopically indistinguishable from that of Crohn's disease. Antibiotic therapy is the treatment of choice for intra-abdominal TB, but surgery is often required for complications, or to obtain tissue for diagnosis. Complications include obstruction by adhesions, perforation of ulcers (rare), and malabsorption due to extensive mucosal damage or lymphatic obstruction.
Salmonella
Dongyou Liu in Handbook of Foodborne Diseases, 2018
Salmonella Paratyphi A, B, or C causes paratyphoid fever, which is a milder enteric fever with low mortality in contrast to Salmonella typhi, which causes typhoid fever. Both serotypes are solely human pathogen. After penetration of the ileal mucosa, the organisms pass through the lymphatics to the mesenteric lymph nodes, when after a period of multiplication they invade the bloodstream via the thoracic duct. The liver, gall bladder, spleen, kidney, and bone marrow become infected during the first 7–10 days of the incubation period. The interval between ingestion of the organisms and the onset of illness varies with the size of the infecting dose. Enteric fever is characterized by abdominal pain, headache, and diarrhea followed by the onset of fever. Apart from fever, patients may develop splenomegaly (enlarged spleen), myalgia, hepatomegaly (enlarged liver), and bradycardia. Roughly 10% of patients may relapse, die, or encounter serious complications such as typhoid encephalopathy, gastrointestinal bleeding, and intestinal perforation. Intestinal perforation may present with abdominal pain, rising pulse, and falling blood pressure in infected persons.1,17,24–26
Maintaining Hydration in the Short Bowel Patient
John K. DiBaise, Carol Rees Parrish, Jon S. Thompson in Short Bowel Syndrome Practical Approach to Management, 2017
Similarly, the ileum is very efficient at reabsorbing much of the water that is secreted into the more proximal gut. Sodium absorption—and, by extension, water absorption, since water follows sodium—is accomplished in the GI tract in part via passive diffusion down the concentration gradient. This occurs more so in the jejunum than in the rest of the bowel because the intercellular junctions in the jejunum are “leaky,” and hence, jejunal contents can only be iso-osmolar with plasma. Thus, water and small molecules move much more freely into and out of the jejunal lumen— about nine times more so than in the ileum [4]. As a result, the loss of ileum is associated with less concentrated stools as compared with a similar length of lost jejunum [4]. Table 11.1 outlines the approximate expected output depending on type of resection undergone and the remaining bowel anatomy.
Responsive nanosystems for targeted therapy of ulcerative colitis: Current practices and future perspectives
Published in Drug Delivery, 2023
Min Chen, Huanrong Lan, Ketao Jin, Yun Chen
The metabolism process in the body is accelerated by certain intestinal enzymes that are secreted by certain microbial flora in the gastrointestinal tract. Such microbial floras also help in the eradication of several gastrointestinal disorders such as irritable bowel disease and thus have a significant impact on health (Garbern et al. 2011). The growth of existing microbial flora is controlled by the gastrointestinal contents and peristaltic movements. The terminal area of ileum is rich in microbial flora and thus it enrich the colon as well (Peng C-L et al. 2010). The drug from dosage form is released into the colon through the action of certain enzymes i.e. azoreductase, glycosidase etc. that is released by microbial flora into the colon. Moreover, gut flora have the ability to hydrolyze the certain polysaccharides, thus delivery polymers of this nature can be hydrolyzed by floral enzymes that will deliver the drug cargo efficiently (Nicholls et al. 2013). Therefore, selection of the polymers/other components liable to microbial degradation should be considered for proper release of the loaded contents in the right targeted site of the GI.
Meckel’s Diverticulum with Multiple Sprouts at the Tip in a Child
Published in Fetal and Pediatric Pathology, 2023
Gang Shen, Binghui Jin, Lu Feng, Zhe Fan
An 8-year-old boy presented with pain in the right lower abdomen for two weeks. The boy had been taken to clinic by his parents and antibiotic treatment had not been effective. He had no fever or nausea. A blood test showed a high neutrophilic granulocyte percentage (70.3%), and an abdominal computerized tomography (CT) scan illustrated an appendix pneumatosis. At surgery, the appendix looked normal. MD with multiple sprouts (12 sprouts) at the tip of about 10 cm × 3 cm × 3 cm was seen at the opposite edge of the mesentery of the small intestine approx. 40 cm from the ileum, which was congested and edematous (Fig. 1). The MD was removed without difficulty. Postoperative anti-infection treatment, nutritional support, and symptomatic treatment were performed, and the child was discharged after one week. Histologically, there was acute appendicitis. The MD had only small intestinal mucosa without ectopic tissues (Fig. 2). The histology indicated MD; histologically there was a mucosa, submucosa, a variably thinned muscular layer and serosa. The child was followed up for 2 years with no other problems.
Segmental Dilatation of Ileum Involving Bronchogenic Cyst in a Newborn
Published in Fetal and Pediatric Pathology, 2023
Özkan Okur, Malik Ergin, Akgun Oral, Munevver Hosgor
In previous studies, microscopic examinations detected ectopic tissue within the SID, including tissue from the esophagus, stomach, or pancreas [10]. We found a 3 cm bronchogenic cyst centered on the mesenteric border of the dilated intestine which has not been previously described. Ciliated foregut cysts are less common and mostly originate from the esophagus or respiratory tract [15]. It is not surprising that ectopic tissue from the respiratory tract has been found in parts of the upper gastrointestinal tract. However, ciliated epithelium in the primitive mid- and hindgut is infrequent in the literature. Killpack describes a similar cystic duplication to the one presented here [16]. Otter et al describe a cystic duplication of the ileum about one meter from the ileocaecal valve, which contained parts of ciliated epithelium together with the typical mucosa of the stomach [17]. The presence of bronchogenic cysts in the abdomen is an uncommon condition and has never been detected in the intestinal lumen before [15]. In present case; the dilated segment extended more distally than the bronchogenic cyst, and is not the cause of the dilatation/obstruction. This is clearly demonstrated in Figure 3. It has been reported that bronchogenic cysts may occur in the mediastinum, lung, heart, stomach and retroperitoneum [18]. Bronchogenic cyst located in the ileal mesentery was detected once in pediatrics, although it has been described as a few cases in adults [15,18,19].