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Detailed chapter

Diverticular Disease & Diverticulitis — Diverticulitis

CT-staged inflammation of a diverticulum — mild cases may avoid automatic antibiotics; complications need source control.

Diverticulitis is inflammation of a diverticulum. Typical clues are left-lower abdominal pain, fever, and change in bowel habit. Contrast CT confirms the diagnosis and grades uncomplicated versus complicated disease (abscess, perforation, fistula, obstruction). Modern care does not give every mild attack automatic antibiotics; complicated disease needs antibiotics ± drainage or surgery.

Diverticulitis — inflamed diverticulum · educational illustration

Educational schematic. Some structures may be simplified or emphasized for clarity; not an exact anatomical depiction.

© Cengiz Dibekoğlu — illustrative; not for unauthorized use

Figure summary

This educational figure shows: Diverticulitis — inflamed diverticulum.

Who may be a candidate?

  • Adults with suspected or confirmed diverticulitis
  • Patients comparing observation versus antibiotics
  • People recovering from a complicated attack before colonoscopy planning

Possible advantages

  • Separates uncomplicated from complicated pathways
  • Explains why antibiotics are not automatic in every mild case
  • Sets expectations for recovery and when to return urgently

Limits & realistic expectations

  • CT and examination still decide urgency
  • Immunosuppressed patients often need a lower threshold for treatment
  • Colonoscopy is usually deferred in the hot phase

Step-by-step overview

  1. 1

    Confirm severity

    Exam + labs + CT separate mild inflammation from abscess / perforation.

  2. 2

    Choose intensity

    Selected mild cases: symptom control ± selective antibiotics; complicated: source control.

  3. 3

    Support recovery

    Fluids, pain control, diet advancement, and clear red-flag instructions.

  4. 4

    Plan colonoscopy timing

    After inflammation settles if cancer still needs excluding and no recent high-quality exam exists.

  5. 5

    Decide elective surgery later

    Not by attack count alone — complications and quality of life drive the talk.

Key points

  • Uncomplicated versus complicated

    Uncomplicated disease is localized inflammation without abscess, free perforation, fistula, or obstruction. Complicated disease includes those features and usually needs antibiotics, possible drainage, and surgical readiness. Immunosuppression, frailty, and diagnostic uncertainty lower the threshold for imaging and admission.

    • Uncomplicated: localized inflammation
    • Complicated: abscess, perforation, fistula, obstruction
    • CT grades severity
    • Clinical decline overrides a ‘mild’ early scan
  • Antibiotics are selective

    Key note inside

    In selected immunocompetent patients with mild uncomplicated diverticulitis, observation and symptom control without reflexive antibiotics can be appropriate in modern protocols. Fever, elevated inflammatory markers with systemic features, inability to take oral intake, or immunosuppression usually push toward antibiotics and closer monitoring.

  • Abscess and source control

    Key note inside

    Larger abscesses may need percutaneous drainage plus antibiotics. Free perforation with peritonitis is a surgical emergency. Fistulas to bladder, vagina, or skin often lead to elective resection talks after acute sepsis is controlled.

    • Drainable abscess → interventional radiology
    • Diffuse peritonitis → emergency surgery pathway
    • Fistula → elective planning after cooling
  • After the attack

    Diet advances as pain settles. Colonoscopy timing depends on whether a recent high-quality exam already exists and whether the course was complicated or atypical. Elective surgery is discussed later — see the surgery chapter.

  • Warning signs during recovery

    Key note inside

    Worsening pain, high fever, vomiting with inability to pass stool or gas, fainting, or a rigid abdomen need urgent reassessment — do not wait for a routine follow-up slot.

  • Important

    Key note inside

    This page is for education. It is not medical advice and does not replace a visit with your physician.

Frequently asked questions

  • How is uncomplicated diverticulitis treated?

    Selected mild immunocompetent cases may be observed with symptom control; antibiotics are not automatic for every mild attack.

  • When is imaging needed?

    CT helps when diagnosis is uncertain or complications are suspected.

  • When is colonoscopy discussed?

    After appropriate recovery — especially if complicated, atypical, or without a recent high-quality exam.

  • Does a second attack mean mandatory surgery?

    No. Elective resection weighs complications, immunosuppression, quality of life, and preference — not attack count alone.

This page is for education. It is not medical advice and does not replace a visit with your physician.

Medical editor: Assoc. Prof. Cengiz Dibekoğlu, MD · Last medically reviewed: August 2026 · English patient-education chapter.