21 A Investigations in lower GI bleed should be specific and less time consuming Small bowel enteroclysis, which uses a tube to infuse barium, methylcellulose, and air directly into the small bowel, yields better images than simple small bowel follow-through. Because the yield has been reported to be very low and the test is poorly tolerated, it is now rarely used. Capsule endoscopy uses a small capsule with a video camera. capsule endoscopy is an excellent tool for the patient who is hemodynamically stable but continues to bleed, with reported  success  rates  as  high  as  90%  in identifying  a  small bowel  pathology. The hemodynamically stable patient should undergo small bowel enteroscopy. Usually performed with a pediatric colonoscope, it is referred to as push endoscopy. It can reach about 50 to 70 cm past the ligament of Treitz  in most cases and permits endoscopic management of some lesions. Overall, push enteroscopy is successful in 40% of patients . Double-balloon endoscopy is another technique gaining in popularity. Although technically difficult, this approach is capable of providing a complete examination of the small bowel. In expert hands, double-balloon enteroscopy can identify a bleeding source in 77% of cases with occult bleeding, with the yield increasing to over 85% if the endoscopy is per-formed within 1 month of an overt bleeding episode.The advantage of this technique is that as well as visualization,  biopsies can be performed and therapeutic interventions undertaken. To conclude investigations in lower GI bleed have to be specific and have high sensitivity also. Sabiston Take-Home Message: Avoid low-yield tests like BMFT; prioritize endoscopic or capsule evaluation for recurrent occult bleeding.

22 b Endoscopic  reduction  of  sigmoid  volvulus  should  be attempted  in  patients  without  evidence  of bowel  necrosis  or  perforation. An  abdominal  radiograph  should  be obtained  following  endoscopic  detorsion  to  confirm  resolution  of  the  volvulus. A  variant  of  cecal  volvulus  termed  cecal  bascule  is  a condition  in  which  a  mobile  cecum  folds  interiorly  and superiorly  over  a  fixed  ascending  colon  without  rotation on  the  vascular  pedicle. Although  local  ischemia  and  infarction  have been  reported,  vascular  embarrassment  occurs  less  frequently. Take-Home Message: Caecal bascule is less likely to cause gangrene; know which volvulus types need urgent surgery.

23 d  left colic artery Left  colon  replacement  of  the esophagus - Blood  supply  is  provided  through  the  inferior mesenteric  artery,  the  left  colic  artery,  and  the  anastomotic  branch connecting  the  middle  colic  artery.  The  middle  colic  artery  is  divided  near  its  origin  from  the  superior  mesenteric  artery.  For complete mobility of the hepatic flexure, hepatic  flexure,  the  right  colic  vessels  often  must  also  be divided. Short segment colon transposition- The  most  popular  segment  of  colon  to  use  for distal  esophageal  replacement  is  an isoperistaltic  segment of  the  distal  transverse  colon  or  the  descending  left  colon based  on  the  ascending  branch  of  the  left  colic  artery. Best colonic interposition graft is left hemi colon with isoperistaltic anastomosis. It is because of two reasons. First its blood supply is robust and dependable and 2nd because of the size match. Presence of marginal artery between left branch of middle colic artery and ascending branch of left colic artery is critical. Left hemi colon graft is completely based on left colic artery. Middle colic artery is ligated. Right colic artery is also ligated.  This is for left hemi colon graft. The question states that transverse colon is used for colonic interposition. Short segment transverse colon grafts are based on middle colic artery. Take-Home Message: For left colon esophageal graft, preserve left colic artery for vascular supply.

24 a Crohn disease activity index is a medical tool, which helps to quantify the symptoms and problems of Crohn's disease It helps to quantify the disease It helps to assess response to medical therapy Crohn's disease activity index includes Number of liquid or soft stools per day for 7 days - X 2 Abdominal pain graded from 0-3 based on severity each day for 7 days - X 5 General well being assessed from 0-4 -  X 7 Presence of complications (extraintestinal manifestations) - X 20 Taking diphenoxylate/loperamide/opiate/atropine for diarrhoea - maximum weightage- X  30 Presence of an abdominal mass - X 10 Hct of < 0.47 in men and <0.42 in women - X 6 % of deviation from standard weight - X 12 Take-Home Message: CRP is not part of CDAI; focus on clinical parameters and labs like hematocrit for disease assessment.

25 b Moderate differentiation Poor prognostic factors in a polyp are: 1. histologically  poorly  differentiated invasive  carcinoma 2. cancer  cells  observed  in  the lymphovascular  spaces,  there  is  a  more  than  a  10%  chance  of metastases    3. A pedunculated  polyp  with  invasion  to  levels  1,  2,  and  3  has  a low risk  for lymph  node  metastasis  or  local  recurrence  and  complete excision  of  the  polyp  is  adequate  if  the  poor  prognostic  factors mentioned earlier are absent . 4. A sessile polyp containing invasive cancer  has  at least  a  10%  chance  of  metastasis  to  regional  lymph nodes , but  if  the  lesion  is  well  or  moderately  differentiated,  there is  no  lymphovascular  invasion  noted,  and  the  lesion  can  be completely  excised,  the  depth  of  invasion  by  the  cancer  may provide  useful  prognostic  information.  There  is  a high  risk  for lymph  node  and  distant  metastases  associated  with sessile  cancers in  the  rectum,  and  these  lesions  should  be  treated  aggressively. Take-Home Message: Moderately differentiated polyps are not poor prognostic markers; focus on poor differentiation, lymphovascular invasion, and positive margins.

26 a Arthritis,  ankylosing  spondylitis,  erythema  nodosum,  and  pyoderma  gangrenosum  typically  improve  or  completely  resolve after  colectomy. PSC  occurs  in  5%  to  8%  of  patients  with  ulcerative  colitis.  HLA-B8  or HLA-DR3  haplotype  are  10  times  more  likely  to  develop  PSC.  The  risk  for  colon  cancer   in these  patients  is  up  to  five  times  greater   than  in  patients  with ulcerative  colitis  alone. Colectomy  has  no  effect  on  the course  of  PSC. Take-Home Message: PSC does not resolve with colectomy; monitor long-term liver disease even after surgery.

27 c HNPCC (Lynch Syndrome) is associated with a variety of cancers including colorectal, endometrial, gastric, ovarian, and urinary tract cancers. Colorectal cancers occur most commonly in right colon. Endometrial cancer is the **second most common** cancer in HNPCC. Take-Home Message: Colon cancer is the most common; endometrial cancer is also frequently seen—screen women for gynecologic malignancies.

28 a In FAP, the rectum is at highest risk for cancer, followed by sigmoid colon. Surveillance and prophylactic surgery are critical. Take-Home Message: Rectum is the most common site for malignancy in FAP; early intervention is key.

29 a High-grade dysplasia carries significant cancer risk. Total proctocolectomy with ileal pouch-anal anastomosis is preferred to remove all at-risk mucosa. Take-Home Message: High-grade dysplasia in UC warrants total proctocolectomy to prevent cancer.

30 a Splenic flexure is a watershed area between SMA and IMA; thus, it is most prone to ischemia. Take-Home Message: Splenic flexure is the vulnerable site in ischemic colitis; identify watershed areas in vascular compromise.