An Indispensable Parameters of Small Bowel Syndrome Include Etiology, Patho Physiology, Risk Factors, Inherited Syndromes

Small bowel cancer explains the following parameters such as malignancy, common sites, subtypes, symptoms, investigations, management and complications. · Small bowel malignancy: rare, ~1,900 cases/yr in UK; <5% of GI cancers despite comprising 90% of mucosal surface. · Common sites: duodenum (55-82%), jejunum (11-25%), ileum (7-17%). Risk factors, · Subtypes: adenocarcinoma (40%, duodenum, avg. age 66), neuroendocrine tumours (ileum), lymphoma (coeliac disease-related EATL), Kaposi sarcoma (HHV-8, immunocompromised). · Risk factors: Male, age, African ethnicity, celiac disease, Crohn's disease, FAP, and Lynch syndrome are non-modifiable; smoking, alcohol, obesity, poor fiber, and a diet heavy in red meat are modifiable. · Symptoms: non-specific abdominal pain, weight loss, occult/microscopic GI bleeding, anaemia; may cause gastric outlet or small bowel obstruction. · Investigations: FBC (anaemia), iron studies, LFTs (mets), stool FIT, genetic testing; imaging—CT, PET-CT, MRI enterography, capsule endoscopy, biopsy. · Management: Chemotherapy (5-FU, capecitabine, oxaliplatin), immunotherapy (pembrolizumab), radiation (palliative), surgical excision (segmental or Whipple's for duodenal tumors), and careful waiting (low-risk cases). · Complications: obstruction (gastric/small bowel), perforation, iron deficiency anaemia, nmetastasis (liver, lungs, bone, brain), death; prognosis—53% 5-year survival.