Bowel surgery encompasses all surgical procedures of the small and large intestine. The underlying conditions most commonly requiring bowel surgery are malignancies (especially colorectal cancer) and inflammatory processes (e.g., sigmoid diverticulitis). These surgical procedures may require the creation of an artificial bowel outlet (stoma). Depending on the underlying disease process and the planned surgical procedures, a stoma may be temporary or permanent. A permanent stoma is created following a procedure in which continence could not be preserved, whereas a temporary stoma allows for uninterrupted bowel healing (e.g., following surgery). Intestinal stomas are usually loop stomas, consisting of a proximal and a distal end, while end stomas have one opening which functions as an artificial anus. One of the main complications of bowel surgery is anastomosis insufficiency, which may lead to abscess formation, peritonitis, and sepsis.
Basic surgical approaches
The following factors can help maximize surgical efficacy in planned procedures:
- Time surgery to take place in periods in which possible inflammation is absent or low
- Optimum treatment of comorbid conditions prior to surgery
- Adequate preoperative measures to prevent abdominal infection (e.g., antibiotic prophylaxis, intestinal cleansing )
The acute onset of severe illness requiring emergency surgery typically means that preoperative conditions cannot be optimized (see above). This can considerably increase the risk for intraoperative and postoperative complications.
Measures to prevent complications: in a two-stage surgical procedure a temporary stoma is created in a first step to divert stool from diseased portions of the bowel, allowing rest, and is reversed in a second step after healing has occurred.
- Resection with primary anastomosis (preserving intestinal continuity)
- Alternative approach: Hartmann procedure
Stoma (enterostomy, artificial bowel outlet, artificial anus) 
- Indication: allows removal of feces from the body
- Entire loop of bowel is exteriorized
- Usually, parts of the ileum are used (ileostoma).
- Handling: the stoma continually drains bowel contents, requiring continuous use of a stoma bag.
- A protective loop stoma is reversed a few weeks/months following surgery (after sufficient healing of the anastomosis).
- Handling: in colostomy patients, irrigation is an option (controlled evacuation of the bowel to have a period free of output, restoring control) 
- Depending on the indications for the initial operation and the underlying condition, re-anastomosis with restoration of intestinal continuity may be possible 3–4 months following surgery.
Anastomosis insufficiency (anastomotic leak)
- Clinical features
- Revision surgery
- Treating complications (e.g., by giving broad-spectrum antibiotics in the case of infection)
- Endoluminal vacuum-assisted closure therapy
- Complications: abscess formation, , ,
- Definition: spontaneous wound rupture along an incision with fascial dehiscence and possible prolapse of underlying structures/organs; may occur following any type of surgery, but seen particularly often following laparotomy in abdominal surgery.
- Postoperative inflammatory processes in the abdomen
- Wound healing disorders
- Insufficient surgical sutures or poor suturing technique
- Increased pressure in the abdomen caused by coughing or gas
- Premature mobilization of the patient
- Clinical features
- Diagnostics: usually a clinical diagnosis
- Use of adhesive tapes as adjunctive wound support and abdominal binders to prevent further wound dehiscence.
- Mobilization of the patient with great care to avoid an increase in pressure.
- Urgent revision surgery (multiple irrigations and debridement of the wound margins) to prevent evisceration or a hernia later on.
- Usage of a support bandage and a negative-pressure (vacuum) wound dressing if wound heals inadequately.
- In malignancy: (locally) recurrent cancer
- Fecal incontinence, increased stool frequency
- Stomal complications
We list the most important complications. The selection is not exhaustive.