small Intestine Flashcards
(138 cards)
1
Q
❓What are key features of short bowel syndrome?
A
➡️ Diarrhea, malnutrition, fluid and electrolyte loss
➕ Risk of gallstones (↓ bile reabsorption)
➕ Risk of kidney stones (↑ oxalate absorption)
2
Q
……….results from inadequate small bowel length and presents with diarrhea, malnutrition, and fluid-electrolyte disturbances.
A
Short bowel syndrome
3
Q
❓Why are constipation and fecal impaction uncommon in short bowel syndrome?
A
⛔ Because patients usually pass unformed stools due to rapid intestinal transit and malabsorption
4
Q
The clinical hallmarks of short bowel syndrome include ⬜⬜⬜⬜⬜⬜, fluid and electrolyte deficiency, and malnutrition.
A
diarrhea
5
Q
The clinical hallmarks of short bowel syndrome include ⬜⬜⬜⬜⬜⬜, diarrha and malnutrition.
A
fluid and electrolyte imbalance
6
Q
❓What is the most appropriate next step in a patient with SBO showing rising lactate and leukocytosis after 24 hours of conservative treatment?
A
✅ Surgery
📌 Suggests possible strangulation or ischemia
7
Q
❓What are red flag signs of bowel strangulation or ischemia in SBO?
SBO= small bowel obestruction.
A
✅ Increased lactate, leukocytosis
✅clinical deterioration
8
Q
❓What is the initial management of stable SBO due to adhesions?
A
➡️ NPO, IV fluids, NG tube, urinary catheter, and close monitoring
NPO=“nil per os”=nothing by mouth.
9
Q
❓Why is CT scan not the best next step in a deteriorating SBO patient?
A
⛔ It may delay definitive treatment when clinical signs clearly indicate the need for surgery.
10
Q
Surgery is indicated in SBO patients who show signs of ⬜⬜⬜⬜⬜⬜⬜⬜⬜ or ⬜⬜⬜⬜⬜⬜⬜⬜ after failing conservative therapy.
A
strangulation or ischemia
11
Q
Initial management of stable small bowel obstruction includes ⬜⬜⬜, IV fluids, NG tube, and observation.
A
NPO
12
Q
⬜⬜⬜⬜⬜⬜ and ⬜⬜⬜⬜⬜⬜⬜⬜ are lab findings that suggest possible bowel ischemia or strangulation in SBO.
A
Elevated lactate & leukocytosis
13
Q
❓What is the most common cause of small bowel obstruction (SBO) in West?
A
✅ Adhesions following abdominal surgery
14
Q
❓What are key symptoms of SBO?
A
➡️ Colicky abdominal pain,
➡️nausea/vomiting ➡️obstipation
obstipation=severe or complete constipation
15
Q
❓What physical signs suggest SBO complications like strangulation?
A
✅ Localized tenderness
✅rebound
✅ guarding
16
Q
❓What are major complications of SBO?
A
- Massive third-spacing
- Electrolyte imbalances (↓Cl⁻, ↓K⁺)
- Metabolic alkalosis
- Bowel ischemia, perforation, peritonitis, and shock
17
Q
❓How is SBO diagnosed in stable vs. unstable patients?
A
➡️ Stable → CT scan
➡️ Unstable → Abdominal X-ray or USG
18
Q
❓What is the initial non-operative management of SBO?
A
✅ Aggressive IV fluids, broad-spectrum antibiotics, and nasogastric decompression.
19
Q
❓When is surgery indicated in SBO?
A
- ✅ When there is vascular compromise,
- ✅strangulation,
- ✅ perforation
20
Q
The most common cause of SBO is postoperative ⬜⬜⬜⬜⬜⬜⬜.
A
adhesions
21
Q
SBO commonly presents with colicky pain, vomiting, and ⬜⬜⬜⬜⬜⬜⬜⬜⬜ (absence of stool or gas).
A
obstipation
21
Q
Signs of SBO strangulation include localized tenderness, rebound, and ⬜⬜⬜⬜⬜⬜⬜.
A
guarding
21
Q
Massive third-spacing in SBO can lead to ⬜⬜⬜⬜⬜⬜⬜⬜ and hypovolemia.
A
dehydration
📝third spacing = abnormal movement of fluid from the intravascular space (inside blood vessels) into the interstitial space or other non-functional compartments of the body, where it cannot be used by the circulatory system.
21
Q
In stable patients, the preferred imaging modality for SBO is ⬜⬜.
A
CT
22
❓What is the **difference** between ileus and gallstone ileus?
➡️ **Ileus:** functional obstruction (↓ peristalsis)
➡️ **Gallstone ileus:** mechanical obstruction by a gallstone
22
❓What are **common causes** of ileus?
* **Postoperative state**
* **Electrolyte imbalances** (↓K⁺, ↓Na⁺, ↓Mg²⁺)
* **Medications** (opiates, anticholinergics)
* **Infections**, **ischemia**, **retroperitoneal inflammation**
23
❓How is **ileus** diagnosed and treated?
✅ **Diagnosis:** Clinical exam + plain abdominal X-ray
✅ **Treatment:** IV fluids, NG decompression, and correcting the underlying cause
24
❓Where does **gallstone ileus** most commonly cause obstruction?
✅ **Distal ileum** (narrowest part of bowel)
25
❓What are diagnostic** X-ray** findings in gallstone ileus?
* ✅ **SBO pattern** ✅**pneumobilia**
* ✅**calcified stone in RLQ**
26
❓What is the **definitive** treatment for gallstone ileus?
✅ Enterotomy proximal to the obstructing stone
27
⬜⬜⬜⬜ is a **functional** bowel obstruction due to impaired peristalsis, often postoperatively or from electrolyte disturbances.
**Ileus**
28
**Gallstone ileus** is a ⬜⬜⬜⬜⬜⬜⬜⬜ obstruction caused by a stone entering the bowel via a cholecystoenteric fistula.
**mechanical**
## Footnote
📝**"Gallstone ileus"** is a misnomer because it suggests a non-mechanical obstruction, but it's actually a mechanical blockage of the bowel caused by a gallstone
29
In **gallstone ileus**, the stone typically lodges in the ⬜⬜⬜⬜⬜ ⬜⬜⬜⬜ (smallest bowel segment).
**distal ileum**
30
**unique** **X-ray** findings in gallstone ileus include **SBO** pattern, ⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜, and a calcified RLQ stone.
**pneumobilia**
31
❓What are **three categories** of small bowel obstruction causes?
✅**Extraluminal:** adhesions, hernias, tumors
✅**Intramural:** primary tumors
✅**Intraluminal:** gallstones, bezoars, foreign bodies
32
❓Which types of surgeries are **most** associated with adhesive small bowel obstruction?
➡️ **Pelvic operations** (e.g., gynecologic, colorectal, appendectomy)
33
❓What **percentage** of SBOs are caused by hernias in the Western world?
✅ **~10%**
34
❓What **imaging** finding supports the diagnosis of **SBO** on **X-ray**?
* Dilated small bowel loops
* air-fluid levels
* no colonic gas
35
**Adhesions** after ⬜⬜⬜⬜⬜ surgeries like appendectomy and colorectal procedures are especially likely to cause SBO.
**pelvic**
36
**SBO** due to ⬜⬜⬜⬜⬜⬜ typically shows dilated small bowel loops with air-fluid levels and no colonic gas on X-ray.
**adhesions**
37
❓What **percentage** of SBO cases are caused by malignant tumors?
➡️ **~20%**, mostly from **metastatic peritoneal disease**.
38
❓What is the **third** leading cause of small bowel obstruction?
✅ **Incarcerated hernias (~10%)**
39
**Hernias** are the ⬜⬜⬜⬜ leading cause of small bowel obstruction, accounting for around 10% of cases.
**third**
39
❓What is the **most common** precipitating factor for superior mesenteric artery (**SMA**) syndrome?
✅ **Rapid weight loss** — leads to loss of mesenteric fat, narrowing the angle between the SMA and aorta
39
❓What part of the **duodenum** is compressed in **SMA syndrome**?
✅ The **third portion** of the duodenum (horizontal part)
39
❓What are key **symptoms** of SMA syndrome?
➡️ **Nausea**,
➡️ **vomiting**
➡️**epigastric pain**
➡️ **postprandial fullness**
➡️ **weight loss**
40
❓What is another name for superior **mesenteric artery syndrome**?
➡️ **Wilkie syndrome**
40
⬜⬜⬜⬜ ⬜⬜⬜⬜ usually occurs before symptoms and contributes to **SMA syndrome** by narrowing the aortomesenteric angle.
**Weight loss**
40
❓How does **weight loss** contribute to superior mesenteric artery syndrome?
✅ It reduces the **fat cushion** between the **SMA** and **aorta**, leading to **compression** of the third part of the duodenum
41
❓When is **gastrografin** used in **SBO** management?
➡️ In **stable** patients with **partial** obstruction, to aid diagnosis or possibly help resolution (not in unstable or deteriorating cases)
41
❓Why is **colonoscopic decompression** inappropriate for small bowel obstruction?
⛔ Because it is used for **large bowel decompression**, not small bowel
## Footnote
📝**Colonoscopic decompression**
refers to the use of a colonoscope to relieve pressure in the large intestine by removing trapped gas or fecal content.
✅ Main use: Emergency management of large bowel obstruction, especially sigmoid volvulus.
⛔ Not useful for small bowel obstruction, as the scope does not reach that far.
42
**Colonoscopy** is **not** useful in small bowel obstruction because the problem lies in the ⬜⬜⬜⬜⬜ ⬜⬜⬜⬜⬜⬜.
**small intestine**
42
**Initial** management of SBO due to adhesions includes fasting, fluids, NG tube, ⬜⬜⬜⬜⬜⬜ ⬜⬜⬜⬜⬜⬜, and close monitoring.
**urinary catheter**
43
Surgery should **not be delayed** in complete SBO with clear clinical signs in order to perform additional ⬜⬜⬜⬜⬜⬜⬜ ⬜⬜⬜⬜.
**imaging tests**
44
❓What is the treatment of choice for **gallstone ileus** causing small bowel obstruction?
✅ **Enterotomy with stone extraction**
45
❓What are the **three** classic radiographic **findings** of gallstone ileus (**Rigler’s triad**)?
**1**. Dilated bowel loops (SBO)
**2**. Pneumobilia
**3**. Ectopic calcified gallstone (usually in RLQ)
46
❓Where does the gallstone typically **lodge** in gallstone ileus?
✅ **Terminal ileum** or **ileocecal valve** (narrowest part of small bowel)
47
❓Is cholecystectomy with fistula repair done during initial surgery in gallstone ileus?
⛔ **No** – usually deferred to a later, elective procedure
## Footnote
**Cholecystectomy with fistula repair is deferred because:**
➡️ Patient is usually unstable
➡️ Priority is relieving obstruction
➡️ Fistula may close spontaneously
✅ Elective surgery can be done later if needed.
48
Gallstone ileus occurs when a gallstone enters the GI tract through a ⬜⬜⬜⬜⬜⬜⬜⬜ between the gallbladder and intestine.
**fistula**
48
**Rigler’s triad** in gallstone ileus includes SBO, pneumobilia, and a ⬜⬜⬜⬜⬜⬜⬜⬜⬜ stone in the bowel.
**calcified**
49
❓How is an **enterotomy** performed to treat gallstone ileus?
✅ A **longitudinal incision** is made on the small bowel just proximal to the stone,
✅the stone is **milked backward**, removed,
✅and the bowel is **closed transversely** to prevent narrowing.
50
Gallstone ileus occurs when a gallstone enters the GI tract through a ⬜⬜⬜⬜⬜⬜⬜⬜ between the gallbladder and intestine.
**fistula**
51
❓How is gallstone ileus managed in terms of **SBO** and **biliary disease**?
➡️ **SBO:** Enterotomy proximal to the stone → stone removal → closure
➡️ **Biliary disease:** Elective cholecystectomy and fistula repair later
52
Gallstone ileus treatment is divided into **SBO management** with ⬜⬜⬜⬜⬜⬜⬜⬜ and stone removal, and **delayed cholecystectomy** with ⬜⬜⬜⬜⬜⬜ ⬜⬜⬜⬜⬜.
➡️enterotomy
➡️ fistula repair
53
**Initial** treatment of gallstone ileus focuses on relieving ⬜⬜⬜⬜ ⬜⬜⬜⬜⬜ ⬜⬜⬜⬜⬜⬜⬜⬜.
**small bowel obstruction**
54
❓What is the most common **site** of gastrointestinal carcinoid tumors?
✅ **Appendix** (followed by distal small intestine)
54
❓Which **symptom** is most common in intestinal carcinoid?
✅ **Abdominal pain** ± **partial obstruction/diarrhea**
(Flushing & tachycardia occur in < 10 % ⇒ “carcinoid syndrome” is rare.)
55
❓What condition must be present for a carcinoid tumor to cause **carcinoid syndrome**?
✅ **Liver metastases** or a tumor that **bypasses** portal circulation (e.g., **bronchial carcinoid**)
55
❓Why **don’t** all carcinoid tumors cause carcinoid syndrome?
✅ Because their secreted hormones are usually metabolized by the liver **before** reaching systemic circulation.
56
**Carcinoid syndrome** occurs when tumor secretions ⬜⬜⬜⬜⬜ liver metabolism and enter systemic circulation.
**bypass**
57
❓From which **cells** do **carcinoid tumors** arise?
✅ **Kulchitsky** (enterochromaffin) cells
## Footnote
⛔ Not Cajal cells (those are typical for GIST)
58
❓How common are metastases from appendiceal carcinoid ≤ 1 cm?
➡️ **~3 % (very rare)**
59
❓How does **tumor size** influence the metastasis risk of carcinoid tumors?
✅**≤1 cm** → very low risk of metastasis
✅**>2 cm** → high risk of metastasis
59
❓Which **MEN syndrome** is linked to ~10 % of GI carcinoids?
✅ **MEN 1**
## Footnote
📝**MEN1** (Multiple Endocrine Neoplasia type 1) involves:
✅ Parathyroid, Pancreas, Pituitary tumors
🧠 Mnemonic: "**3 P’s**"
**Carcinoid tumors in MEN1?**
⛔ Not part of the classic triad
✅ May rarely occur (e.g., thymic, gastric), especially in MEN1 males
59
The most common **location** of a GI carcinoid tumor is the ⬜⬜⬜⬜⬜⬜⬜.
**appendix**
59
Carcinoid tumors originate from ⬜⬜⬜⬜⬜⬜⬜⬜⬜ cells, not Cajal cells.
**Kulchitsky**
59
**Carcinoid syndrome** (flushing, diarrhea, tachycardia) occurs in ⬜ % of **carcinoid cases**.
< 10
60
Carcinoid tumors ⬜⬜⬜⬜⬜ than 1 cm rarely metastasize.
**smaller**
61
Carcinoid tumors ⬜⬜⬜⬜⬜ than 2 cm have a high risk of metastasis.
**larger**
62
❓Are **bezoars** a common cause of **SBO**?
⛔ **No** — they account for <2% of cases
## Footnote
📝**A bezoar** is a mass of indigestible material that accumulates in the gastrointestinal (GI) tract, usually in the stomach.
🔹 **Types of bezoars:**
**Phytobezoa**r – made of plant fibers (e.g., celery, pumpkin, persimmons)
**Trichobezoar** – made of hair (seen in trichotillomania)
**Pharmacobezoar** – from medications or tablets
63
❓An **elderly** patient with **SBO**, no prior surgery, and pneumobilia on CT likely has what condition?
✅ **Gallstone ileus**
64
❓Why is bile duct exploration **not** usually required in gallstone ileus?
➡️ **Because** the stone has already exited the gallbladder into the bowel via a **fistula**
65
Gallstone ileus is treated surgically with a ⬜⬜⬜⬜⬜⬜⬜ ⬜⬜⬜⬜⬜⬜⬜ made just proximal to the stone.
**longitudinal enterotomy**
66
❓What **electrolyte abnormality** is commonly seen in patients with vomiting due to SBO?
✅ **Hypokalemia**
67
❓Why does vomiting lead to hypokalemia?
➡️ Loss of HCl → **metabolic alkalosis** → increased aldosterone → renal K⁺ wasting
68
❓What acid-base disorder is typically caused by prolonged vomiting?
✅ **Metabolic alkalosis**
68
❓Does vomiting cause hyper- or hypochloremia?
⛔ **Hypochloremia** — due to loss of HCl
69
pathophysiologic mechanism of **hypokalemia** in vomiting
**1**. **Na⁺/H⁺ antiporter** (labeled ①)
Loss of gastric H⁺ through vomiting → metabolic alkalosis
To compensate, the body exports more H⁺ out of the cell via this antiporter, in exchange for Na⁺
**2**. **Na⁺/K⁺ ATPase** (labeled ②)
The increase in intracellular Na⁺ stimulates the Na⁺/K⁺ ATPase, which pumps Na⁺ out and K⁺ into the cell
**3**. **Result: Hypokalemia** (labeled ③)
More K⁺ moves into cells, and aldosterone (stimulated by hypovolemia) causes further renal K⁺ excretion, leading to low serum K⁺
## Footnote
📝 **Summary:**
➡️ Vomiting → H⁺ loss → ↑Na⁺/H⁺ exchanger activity
➡️ ↑Na⁺ influx → ↑Na⁺/K⁺ ATPase activity
➡️ K⁺ shift into cells + renal loss → hypokalemia
70
❓What **sodium abnormality** is expected with dehydration from vomiting?
➡️ Usually **hypernatremia** due to volume contraction
71
❓What metabolic and electrolyte abnormalities result from persistent **vomiting**?
✅ **Hypochloremic metabolic alkalosis** and **hypokalemia**
72
❓Why does **pneumobilia** occur in gallstone ileus?
✅ Due to a **fistula** between the gallbladder and bowel, allowing bowel gas to enter the biliary tree
73
⬜⬜⬜⬜⬜⬜⬜⬜⬜ is the unique and pathognomonic imaging finding for gallstone ileus.
**Pneumobilia**
73
❓What **physical exam** findings are typical in early small bowel obstruction?
* ✅ **Colicky abdominal pain**
* ✅ **hyperactive bowel sounds**
* ✅ **borborygmi**
## Footnote
📝**Borborygmi**=are the loud, gurgling bowel sounds caused by the movement of gas and fluids through the intestines.
74
Initial SBO treatment includes IV fluids, ⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜ tube decompression, and possibly surgery.
**nasogastric**
74
❓What **abdominal sound** is often heard early in **SBO**?
✅ **Borborygmi** (loud, hyperactive bowel sounds)
75
**Early SBO** may present with **hyperactive** bowel sounds called ⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜.
**borborygmi**
76
❓What is **Meckel's diverticulum**?
✅ A **true congenital diverticulum** caused by failure of vitelline duct regression.
🧠 Contains all layers of the intestinal wall
76
❓What is the **next best step** in a patient with inflamed **Meckel’s** diverticulum found on **laparoscopy**?
✅ **Resection** of the diverticulum (segmental small bowel resection)
77
❓When is Meckel’s diverticulum **surgically** resected?
✅ If **symptomatic** or in asymptomatic patients with **risk factors:**
* < 50 years old
* male
* >2 cm,
* palpable mass
* ectopic tissue
## Footnote
📝 Although the anatomical anomaly occurs in both sexes, males are 2–4 times more likely to develop complications like bleeding, obstruction, or inflammation.
77
❓What is the most common **congenital anomaly** of the small intestine?
✅ **Meckel’s diverticulum**
77
❓What is the best **noninvasive** test for Meckel’s diverticulum?
✅ **99mTc-pertechnetate scan**.
77
The treatment for an inflamed Meckel’s diverticulum found on laparoscopy is ⬜⬜⬜⬜⬜⬜⬜⬜ of the diverticulum.
**resection**
78
❓Why is a right hemicolectomy or subtotal colectomy **not** indicated for Meckel’s diverticulum?
✅ Because the diverticulum is in the **small intestine**, not the colon
78
✂️Treatment of symptomatic Meckel’s diverticulum is by ⬜⬜⬜⬜⬜⬜⬜ ⬜⬜⬜⬜⬜⬜⬜ of small bowel.
**segmental resection**
78
✂️Meckel's diverticulum is a true diverticulum caused by failed regression of the ⬜⬜⬜⬜⬜⬜⬜ ⬜⬜⬜.
**vitelline duct**
79
❓Which **arteries** supply the **duodenum** with blood?
✅ **Celiac artery** + **Superior mesenteric artery**
79
❓Why is **MRCP** not useful in gallstone ileus?
✅ Because it **does not** visualize distal ileal obstructions
79
✂️Gallstone ileus causes mechanical bowel obstruction due to a large stone passing via a ⬜⬜⬜⬜⬜⬜ to the intestine.
**fistula**
80
✂️⬜⬜⬜⬜⬜⬜⬜⬜⬜ is the presence of **air** in the biliary tree and is a key **imaging** finding in gallstone ileus.
**Pneumobilia**
80
❓What part of the s**mall bowel** is supplied by **both** the celiac and superior mesenteric arteries?
✅ **The duodenum**
81
❓Which **artery** supplies most of the small bowel (**jejunum and ileum**)?
✅ **Superior mesenteric artery (SMA)**
82
❓Which vein joins the splenic vein to form the portal vein?
✅ **Superior mesenteric vein**
83
✂️The superior mesenteric artery passes anterior to the ⬜⬜⬜⬜⬜⬜⬜ process of the pancreas and the third part of the duodenum.
**uncinate**
84
❓Which arteries form an **anastomotic arcade** supplying the duodenum and pancreatic head?
✅ **Superior & inferior** pancreaticoduodenal arteries (from the celiac and SMA)
85
❓How does the vascular supply differ between the **jejunum** and the **ileum**⁉️
**Arcades**:
* **Jejunum** :Fewer (1–2 loops)
* **Ileum**:Multiple, complex arcades
86
✂️celiac trunk Supplies the proximal duodenum via the⬜⬜⬜⬜⬜
**gastroduodenal artery**
87
❓What is the **pathophysiology** behind gallstone ileus and the classic radiographic finding⁉️
➡️ Gallstone ileus occurs when a large stone enters the bowel through a **cholecystoenteric fistula** (typically gallbladder–duodenum) ➕ causes obstruction, often in the terminal ileum.
87
🔹 **Conservative** management is preferred in hemodynamically **stable** SBO patients **without** signs of ischemia or perforation.**T/F?**
✅ **True**
87
❓What is the **first step** in the treatment of small bowel obstruction (SBO)⁉️
➡️ Fluid resuscitation with IV **isotonic fluids** (e.g., Lactated Ringer)
88
❓Which type of small intestinal neuroendocrine tumor (NET) is most likely to cause carcinoid syndrome⁉️
➡️ A tumor with **liver metastases**, such as a 2 cm tumor that has spread to the liver
📌 Carcinoid syndrome requires bypassing hepatic first-pass metabolism (e.g., liver mets or extra-GI origin).
88
❓What is the most common **site** for gastrointestinal stromal tumors **(GISTs)**⁉️
➡️ **Stomach** (40–60%)
➡️ **Small intestine** (20–40%)
➡️ **Colon/rectum** (5–15%)
88
**GISTs** originate from
**Cajal cells**
89
**GISTs** most commonly arise in the ____ (40–60%), followed by the ____ (20–40%) and the ____ (5–15%).
➡️ **Stomach**, **small intestine**, **colon/rectum**
90
Diagnosis of GIST?
**EUS-FNA** + **c-Kit (CD117) staining**
91
❓What is the appropriate **immediate** treatment for **carcinoid crisis** during **surgery** (flushing, hypotension, arrhythmias)?
➡️ **IV Octreotide bolus** (50–100 µg), followed by continuous infusion (50 µg/hr)
92
❓What is **carcinoid crisis** and how is it managed during surgery?
➡️ A **life-threatening** complication in patients with **neuroendocrine tumors**, triggered by **anesthesia**; it presents with flushing, hypotension, bronchospasm, and tachycardia.
92
❓What is the most likely cause of fatigue, glossitis, paresthesia, and gait disturbance 2 years **after terminal ileum resection** in a Crohn’s patient?
➡️ **Vitamin B12 deficiency**.
📌 B12 is absorbed in the terminal ileum and deficiency presents with neurological signs (e.g. decreased proprioception, vibration sense) and glossitis.
93
which **vitamin deficiency** can cause **subacute combined degeneration**(**SCD**) of the spinal cord?
➡️ **Vitamin B12**
94
🔹 Resection of the terminal ileum increases the risk of deficiency in vitamin _____, leading to neurologic symptoms like paresthesia and ataxia.
➡️ **B12**
94
🔹 The tongue finding characteristic of vitamin B12 deficiency is an _____ and smooth tongue.
➡️ **enlarged**
95
❓Where is vitamin B12 **absorbed** in the GI tract?
➡️ **Terminal ileum**
96
❓Which GI diseases or surgeries can impair **vitamin B12 absorption**⁉️
➡️ **Crohn’s disease** and **terminal ileum resection**
97
❓What is the most likely cause of small bowel obstruction in a healthy patient with no prior abdominal surgeries⁉️
➡️ **Incarcerated femoral hernia**
97
❓Why is incarcerated femoral hernia a likely cause of SBO in patients **without** prior surgeries⁉️
➡️ Femoral hernias occur **without** prior surgery and account for ~10% of SBOs.
📌 High risk of strangulation
97
❓What are the most common causes of small bowel obstruction (**SBO**)⁉️
🔹 **Adhesions** (60%)
🔹 **Neoplasms** (20%)
🔹 **Hernias** (10%)
🔹 **Crohn’s disease** (5%)
🔹 **Miscellaneous** (<5%)
98
❓Which factor favors **spontaneous closure** of an enterocutaneous fistula⁉️
✅ **Long fistula tract** (>10 cm)
98
❓What are the **key factors** that prevent spontaneous fistula closure ⁉️
(**FRIENDS** mnemonic)
🔻 Foreign body
🔻 Radiation
🔻 Infection
🔻 Epithelialization of tract
🔻 Neoplasm
🔻 Distal obstruction
🔻 Short tract (<2 cm)
98
🔹 A fistula output of >________ mL/24h is associated with poor spontaneous healing.
➡️ **500**
