Diverticulosis is a common condition characterized by small, bulging pouches, called diverticula, that form along the lining of the large intestine. While these pouches generally do not cause symptoms, inflammation or infection leads to diverticulitis. A flare-up is often accompanied by noticeable changes in bowel habits and stool appearance. Recognizing these alterations is important for identifying an acute episode and seeking appropriate care.
Why Diverticulitis Alters Bowel Movements
The physical changes in stool appearance during a flare result directly from inflammation within the colon wall. When diverticula become infected, the surrounding tissue swells and thickens, which can narrow the internal passageway of the large intestine. This mechanical narrowing, known as a stricture, changes how waste material is processed and moved along the colon.
Inflammation also affects the normal muscular contractions responsible for propelling stool forward. This disruption in motility can lead to sluggish movement, causing constipation, or rapid transit, resulting in diarrhea. Furthermore, the small blood vessels near the inflamed pouches can rupture, creating the potential for visible blood to mix with the stool.
Specific Stool Characteristics During an Acute Flare
Blood in Stool
The presence of blood in the stool is a key change during a diverticulitis flare. Bleeding occurs when a blood vessel in the wall of a diverticulum is irritated or ruptures due to inflammation. This blood often appears as bright red streaking on the stool or in the toilet bowl, indicating a source of bleeding lower in the gastrointestinal tract. Less commonly, blood may appear maroon or black and tarry, which signals a bleed that is higher up or more significant.
Consistency and Shape
Stool consistency often changes during an acute episode. Inflammation can cause the colon to release extra fluid, resulting in loose, watery stools characteristic of diarrhea. Conversely, colon narrowing and the pain associated with a flare can lead to constipation, producing hard, pellet-like pieces of stool.
Changes in shape are a direct manifestation of the narrowed colon passageway. When inflammation causes strictures, the stool may be forced into an abnormally thin shape, appearing ribbon-like or pencil-thin. Stool may also appear coated in mucus, which is a sign of irritation or infection in the colon lining.
Accompanying Symptoms of Diverticulitis
Stool changes are typically accompanied by physical symptoms signaling an active infection. The most common symptom is abdominal pain, usually located in the lower left side of the abdomen. This pain is often persistent and can range from mild tenderness to severe onset that worsens over several days.
The body’s response to infection often includes systemic symptoms such as a fever, typically exceeding 100.4 degrees Fahrenheit, and chills. Nausea and vomiting are also frequently experienced alongside the abdominal discomfort.
When to Consult a Healthcare Provider
Any noticeable or persistent change in stool should prompt a consultation with a healthcare provider. Immediate medical attention is necessary if urgent symptoms are present, as these indicate a serious issue.
Urgent signs include a high or persistent fever accompanied by severe abdominal pain. Large amounts of rectal bleeding, especially if it is heavy, continuous, or results in black, tarry stools, also requires immediate evaluation. Persistent vomiting that prevents a person from keeping down fluids is a serious concern due to the risk of dehydration. Professional medical assessment is necessary to confirm diverticulitis and begin appropriate treatment.