This is the most common form of diverticulitis. Patients present with acute, steady, left lower abdominal discomfort. This may be associated with alteration in bowel habits with either constipation or diarrhea. There may be a low-grade fever but the patient is not tachycardic. Examination reveals mild left lower quadrant tenderness without an appreciable mass. 

Treatment can be carried out on an outpatient basis and consists of clear liquids by mouth and a broad-spectrum oral antibiotic for 7-10 days. Trimethoprim-sulfamethoxazole, 1 tab BID, and metronidazole, 250mg QID, or ciprofloxacin, 500mg BID, and metronidazole are good combinations to use.  Solid foods may be started as symptoms subside and a high fiber diet instituted after resolution of the inflammation.  Follow-up evaluation should include flexible sigmoidoscopy and barium enema after the inflammation has resolved, usually at 3-4 weeks.

(8)     Pericolic or Mesenteric Abscess

The patient with this stage of inflammation will complain of moderate to severe left lower abdominal pain and anorexia. Alteration in normal bowel habits with constipation or diarrhea will occur. Abdominal exam reveals a tender mass and voluntary guarding in the lower abdomen. Rebound tenderness or referred rebound tenderness may be present. Pyrexia and tachycardia are usually present.

(a)     A chest x-ray along with flat and upright abdominal films can assist with excluding the presence of free intraperitoneal air or intestinal obstruction.  Urinalysis can exclude urinary tract infection, fecaluria, and ureterolithiasis. Leukocytosis is usually present. 

(b)     The patient is best treated with hospitalization, bowel rest, IV hydration, and IV antibiotics. Antibiotics should cover both aerobes and anaerobes. Cefoxitin or Unasyn are good single agents to start with. If patients appear more toxic, then an aminoglycoside with metronidazole and ampicillin for enterococcus coverage may be used. Imipenem or Trovan may be used as a single agent in this situation. Nasogastric suction is unnecessary except for persistent emesis or obstruction. A water-soluble contrast enema or CT scan is useful to confirm the diagnosis in atypical presentations or if not improving within 48 hours.

(c)     Again, most of these patients will resolve on medical management and should undergo further evaluation after resolution of the inflammation.

(9)     Generalized Purulent or Feculent Peritonitis

When the inflamed colon or abscess freely perforates into the peritoneal cavity generalized peritonitis and the true “acute abdomen” will occur. Patients will complain of severe diffuse abdominal pain with anorexia, nausea and vomiting. The patient is tachycardic, pyrexic, and dehydrated. Severe tachycardia and hypotension are signs of septic shock. On examination, the patient will have a diffusely tender abdomen with involuntary guarding, rebound and percussion tenderness, and absent or rare bowel sounds. An upright CXR and acute abdominal series may reveal free intraperitoneal air. The first step in management of peritonitis is volume replacement with IV fluids (NS or LR). Treatment also includes insertion of an NG tube, Foley catheter, and administration of IV antibiotics. Surgical exploration should follow immediately. Surgical treatment involves resection of the involved colon, abdominal irrigation, drainage of any abscess and formation of a colostomy. Post-operative complications of ARDS, stress ulcers, ongoing sepsis, and possible multi-organ system failure make early recognition and rapid resuscitation and treatment of this entity essential in decreasing its morbidity and mortality.

(10)   Diverticular Hemorrhage

Diverticular bleeding occurs in 5-15 percent of patients with diverticulosis. The average age is 65 years. Diverticular hemorrhage is usually massive but self-limited. Bleeding stops spontaneously with supportive management in 70 – 95 percent of cases. Recurrent episodes occur in 25 percent of patients. After a second hemorrhage, the chance of a third increases to 50%.

Classic bleeding in diverticulosis is painless and associated with the sudden passage of a large amount of bright red or maroon-colored stool. Orthostatic symptoms may ensue. Mild cramping abdominal pain is due to the cathartic effect of the intracolonic blood. Similar type bleeding may arise from other sources such as angiodysplasias, vascular malformations, Meckel’s diverticulum, or rarely, carcinoma. Associated symptoms of recent diarrhea suggest inflammatory bowel disease or infectious etiology.

Patients with massive lower GI bleeding need to be approached similar to those with UGI hemorrhage. Institute IV fluid resuscitation immediately while initially assessing patient.  Document patient’s vital signs and hemodynamic stability. Draw blood for type and cross, CBC, electrolytes, liver functions, and coagulation profile. Document duration and amount of bleeding, presence of melena, or prior history of bleeding.  A history of medication use to include ASA, NSAIDS, coumadin, or alcohol abuse, or a history of liver or renal disease may predispose the patient to rectal bleeding.  Abdominal exam is usually unremarkable. Digital anal exam reveals gross evidence of rectal bleeding.  Anoscopy and proctoscopy should be performed to eliminate an anorectal source of bleeding.  A nasogastric (NG) tube is placed to exclude an upper GI source.  If the NG aspirate does not contain bile an upper source cannot be excluded, but is less likely. If the aspirate contains evidence of bleeding an upper GI source is most likely and an urgent esophageal gastroduodenoscopy (EGD) will be required.  All patients with an acute major GI bleed must be transferred to an MTF as soon as possible.

Reference

(a)     Gordon, Philip H.: Diverticular Disease of the Colon. In: Principles and Practice of Surgery for the Colon, Rectum, and Anus, 2^nd Edition. St.Louis: QMP. 1999: 975-1037.                                                

Submitted by CAPT H.R. Bohman, MC, USN, General Surgery Specialty Leader, Naval Hospital Camp Pendleton, CA (1999).