The small and large intestines are in constant motion to wave the digested food towards the rectum. This movement typical of the gastrointestinal tract is called peristalsis. The degree of peristalsis can be seen particularly well in diarrheal diseases. But intestinal obstruction can trigger violent intestinal movements.
The result is severe abdominal pain, which may be piercing, dull or convulsive (colicky) depending on the cause. First, the pain can be fairly well assigned to a specific region, but over time, the discomfort extends to the entire upper and lower abdomen. Intestinal obstruction, in which obstructions in the intestine impair or prevent the further transport of the intestinal contents, is called mechanical intestinal obstruction (ileus).
What causes a mechanical ileus?
Overall, the passage disorder is more often localized in the small intestine than in the colon (small intestinal ileus in 80 percent, large intestine in 20 percent of cases). Mechanical ileus is also referred to as obturation, as the intestinal clearing is narrowed (obturated) from the inside or outside.
Causes of mechanical ileus can be:
- Adhesions and Brids (bonds); a very common reason, especially after a preoperative operation
- constricting tumors (often in the colon as colon carcinoma)
- Foreign bodies (for example gallstones, fecal stones)
- Encryption / constrictions
- Scarring in the healing (for example in diverticulitis, Crohn's disease, ulcerative colitis)
- Hernias (connective tissue sacs) in which the intestine and its contents become wedged; especially inguinal and testicular hernias
After each operation in the abdominal cavity, adhesions (= adhesions) between the intestinal loops can develop or scarred strands (= Briden) form, whereby the intestine diameter is concentrated. Adhesion or bridle repair after surgery can occur just days after abdominal surgery, but only months or years later. If the affected person has undergone several abdominal preoperative surgeries, the likelihood that he will later develop an adhesive or bridle joint increases significantly.
Mechanical ileus: other causes
Scarring can also occur in the abdomen after severe injury, extensive inflammatory bowel disease or healed peritonitis (peritonitis). In peritonitis (for example, in appendicitis with intestinal perforation), the risk of subsequent ileus development is much higher than after an appendix removal without breakthrough.
In a Strangulationsileus the intestinal wall blood flow is impaired because the intestinal vessels are twisted or pinched. In a Volvulus there is a twisting of a bowel loop on its own axis, in an invagination, a section of the intestine inverts in the form of a fold over the next adjacent intestinal piece.
In case of inflammatory bowel disease or malignant tumors, the diameter of the bowel can be reduced so much that only a thread-like passage is possible. Due to the violent intestinal movements (peristalsis), which want to move the stool through this thread-like passage in the direction of the rectum, even so-called overflow diarrhea (watery diarrhea) can arise. Large gallstones that break from the gallbladder directly into the colon and feces or foreign bodies are among the rarer causes of mechanical ileus.