Patients (often infants) present acutely with midgut volvulus, manifested by bilious vomiting, crampy abdominal pain, abdominal distention, and the passage of blood and mucus in their stools. Patients with chronic, uncorrected malrotation can have recurrent abdominal pain and vomiting.

Malrotation can also be asymptomatic.

This can lead to a number of disease manifestations such as:

- Acute midgut volvulus

- Chronic midgut volvulus

- Acute duodenal obstruction

- Chronic duodenal obstruction

- Internal herniation

- Superior mesenteric artery syndrome

Regardless of cause, volvulus causes symptoms by two mechanisms:

- Bowel obstruction manifested as abdominal distension and bilious vomiting.

- Ischemia (loss of blood flow) to the affected portion of intestine.

Depending on the location of the volvulus, symptoms may vary. For example, in patients with a cecal volvulus, the predominant symptoms may be those of a small bowel obstruction (nausea, vomiting and lack of stool or flatus), because the obstructing point is close to the ileocecal valve and small intestine. In patients with a sigmoid volvulus, although abdominal pain may be present, symptoms of constipation may be more prominent.

Volvulus causes severe pain and progressive injury to the intestinal wall, with accumulation of gas and fluid in the portion of the bowel obstructed. Ultimately, this can result in necrosis of the affected intestinal wall, acidosis, and death. This is known as a closed loop obstruction because there exists an isolated ("closed") loop of bowel. Acute volvulus often requires immediate surgical intervention to untwist the affected segment of bowel and possibly resect any unsalvageable portion.

Volvulus occurs most frequently in middle-aged and elderly men. Volvulus can also arise as a rare complication in persons with redundant colon, a normal anatomic variation resulting in extra colonic loops.

Sigmoid volvulus is the most-common form of volvulus of the gastrointestinal tract. and is responsible for 8% of all intestinal obstructions. Sigmoid volvulus is particularly common in elderly persons and constipated patients. Patients experience abdominal pain, distension, and absolute constipation.

Cecal volvulus is slightly less common than sigmoid volvulus and is associated with symptoms of abdominal pain and small bowel obstruction.

Volvulus can also occur in patients with Duchenne muscular dystrophy due to the smooth muscle dysfunction.

The diagnosis is suspected based on polyhydramnios in uteru, bilious vomiting, failure to pass meconium in the first day of life, and abdominal distension. The presentations of NBO may vary. It may be subtle and easily overlooked on physical examination or can involve massive abdominal distension, respiratory distress and cardiovascular collapse. Unlike older children, neonates with unrecognized intestinal obstruction deteriorate rapidly.

Prognosis is usually very good, although complications are more likely to occur when there are serious congenital anomalies. Late complications may occur in about 12 percent of patients with duodenal atresia, and the mortality rate for these complications is 6 percent.

Intestinal atresia is a malformation where there is a narrowing or absence of a portion of the intestine. This defect can either occur in the small or large intestine.

The diagnosis of duodenal atresia is usually confirmed by radiography. An X-ray of the abdomen shows two large air filled spaces, the so-called "double bubble" sign. The air is trapped in the stomach and proximal duodenum, which are separated by the pyloric sphincter, creating the appearance of two bubbles visible on x-ray. Since the closure of the duodenum is complete in duodenal atresia, no air is seen in the distal duodenum.

Atresias occurring distal to the duodenum are usually caused by vascular accidents or ischemic insult, such as jejunoileal atresia.

Midgut volvulus occurs in people (usually babies) that are predisposed because of congenital intestinal malrotation. Segmental volvulus occurs in people of any age, usually with a predisposition because of abnormal intestinal contents (e.g. meconium ileus) or adhesions. Volvulus of the cecum, transverse colon, or sigmoid colon occurs, usually in adults, with only minor predisposing factors such as redundant (excess, inadequately supported) intestinal tissue and constipation.

Signs and symptoms of DIOS include a sudden onset of crampy abdominal pain, vomiting, and a palpable mass (often in the right lower quadrant) in the abdomen. The characteristic abdominal pain is typically located in the center or right lower quadrant of the abdomen. X-rays of the abdomen may reveal stool in the colon and air-fluid levels in the small intestines.

Diverticular disease can present with painless rectal bleeding as bright red blood per rectum. Diverticular bleeding is the most common cause of acute lower gastrointestinal bleeding. However, it is estimated that 80% of these cases are self-limiting and require no specific therapy.

Neonatal bowel obstruction (NBO) or neonatal intestinal obstruction is the most common surgical emergency in the neonatal period. It may occur due to a variety of conditions and has an excellent outcome based on timely diagnosis and appropriate intervention.

Some people with diverticulosis complain of symptoms such as cramping, bloating, flatulence, and irregular defecation. However, it is unclear if these symptoms are attributable to the underlying diverticulosis or to coexistent irritable bowel syndrome.

Diverticular disease was found associated with a higher risk of left sided colon cancer.

DIOS is sometimes classified by the degree of obstruction as incomplete or complete DIOS.

Intestinal atresias are often discovered before birth: either during a routine sonogram which shows a dilated intestinal segment due to the blockage, or by the development of polyhydramnios (the buildup of too much amniotic fluid in the uterus). These abnormalities are indications that the fetus may have a bowel obstruction which a more detailed ultrasound study can confirm.

Some fetuses with bowel obstruction have abnormal chromosomes. An amniocentesis is recommended because it can determine not only the sex of the baby, but whether or not there is a problem with the chromosomes.

A Richter's hernia occurs when the antimesenteric wall of the intestine protrudes through a defect in the abdominal wall. This is discrete from other types of abdominal hernias in that only one intestinal wall protrudes through the defect, such that the lumen of the intestine is incompletely contained in the defect, while the rest remains in the peritoneal cavity. If such a herniation becomes necrotic and is subsequently reduced during hernia repair, perforation and peritonitis may result. A Richter's hernia can result in strangulation and necrosis in the absence of intestinal obstruction. It is a relatively rare but dangerous type of hernia.

Richter's hernia have also been noted in laparoscopic port-sites, usually when the fascia is not closed for ports larger than 10mm. A high index of suspicion is required in the post operative period as this sinister problem can closely mimic more benign complications like port-site haematomas.

Treatment is resection and anastomosis.

Mortality increases with delay in surgical intervention.

Decreased propulsive ability may be broadly classified as caused either by bowel obstruction or intestinal atony or paralysis. However, instances with symptoms and signs of a bowel obstruction occur, but with the absence of a mechanical obstruction, mainly in acute colonic pseudo-obstruction, Ogilvie's syndrome.

Symptoms of ileus include, but are not limited to:

- moderate, diffuse abdominal discomfort

- constipation

- abdominal distension

- nausea/vomiting, especially after meals

- vomiting of bilious fluid

- lack of bowel movement and/or flatulence

- excessive belching

Uterine tears often occur a few days post parturition. They can lead to peritonitis and require surgical intervention to fix. Uterine torsions can occur in the third trimester, and while some cases may be corrected if the horse in anesthetized and rolled, others require surgical correction.

Diaphragmatic hernias are rare in horses, accounting for 0.3% of colics. Usually the small intestine herniates through a rent in the diaphragm, although any part of the bowel may be involved. Hernias are most commonly acquired, not congenital, with 48% of horses having a history of recent trauma, usually through during parturition, distention of the abdomen, a fall, or strenuous exercise, or direct trauma to the chest. Congenital hernias occur most commonly in the most ventral part of the diaphragm, while acquired hernias are usually seen at the junction of the muscular and tendinous sections of the diaphragm. Clinical signs usually are similar to an obstruction, but occasionally decreased lung sounds may be heard in one section of the chest, although dyspnea is only seen in approximately 18% of horses. Ultrasound and radiography may both be used to diagnose diaphragmatic herniation.

The symptoms of short bowel syndrome can include:

- Abdominal pain

- Diarrhea and steatorrhea (oily, bulky stool, which can be malodorous)

- Fluid depletion

- Weight loss and malnutrition

- Fatigue

Persons with short bowel syndrome may have complications caused by malabsorption of vitamins and minerals, such as deficiencies in vitamins A, D, E, K, B (folic acid), and B, calcium, magnesium, iron, and zinc. These may appear as anemia, hyperkeratosis (scaling of the skin), easy bruising, muscle spasms, poor blood clotting, and bone pain.

Usually the patient has abdominal distention, pain and altered bowel movements. There may also be nausea and vomiting.

Intestinal failure is decreased intestinal function such that nutrients, water, and electrolytes are not sufficiently absorbed. Short bowel syndrome is when there is less than of working bowel and is the most common cause of intestinal failure.

Signs and symptoms include early satiety, nausea, vomiting, extreme "stabbing" postprandial abdominal pain (due to both the duodenal compression and the compensatory reversed peristalsis), abdominal distention/distortion, burping (eructation), external hypersensitivity or tenderness of the abdominal area, reflux, and heartburn. In infants, feeding difficulties and poor weight gain are also frequent symptoms.

In some cases of SMA syndrome, severe malnutrition accompanying spontaneous wasting may occur. This, in turn, increases the duodenal compression, which worsens the underlying cause, creating a cycle of worsening symptoms.

"Food fear" is a common development among patients with the chronic form of SMA syndrome. For many, symptoms are partially relieved when in the left lateral decubitus or knee-to-chest position, or in the prone (face down) position. A Hayes maneuver (pressure applied below the umbilicus in cephalad and dorsal direction) elevates the root of the SMA, also slightly easing the constriction. Symptoms can be aggravated when leaning to the right or taking a supine (face up) position.

Umbilical cord ulceration and intestinal atresia is a rare congenital disease that leads to intestinal atresia, umbilical cord ulceration and severe intrauterine haemorrhage. Only 15 cases have so far been reported, though newer studies are beginning to conclude that this disease has a higher incidence rate than has been previously reported. A particular study has given intestinal atresia and umbilical cord ulceration a clear link after 5 such cases were reported at the time of publication.

Ogilvie syndrome may occur after surgery, especially following coronary artery bypass surgery and total joint replacement. Drugs that disturb colonic motility (e.g., anticholinergics or opioid analgesics) contribute to the development of this condition.