What are the typical symptoms and management options for a female patient with suspected Irritable Bowel Syndrome (IBS)?

Symptoms of Irritable Bowel Syndrome

IBS is diagnosed by recurrent abdominal pain associated with disturbed bowel habit, where pain is relieved by defecation or associated with changes in stool frequency or consistency, lasting at least 12 weeks over the past year. 1

Core Gastrointestinal Symptoms

The cardinal features that define IBS include:

• Abdominal pain or discomfort that is typically colicky, can occur at any site but most commonly on the left side, and is characteristically relieved by defecation 1, 2
• Altered stool frequency - either more frequent (>3 times daily) or less frequent (<3 times weekly) 1
• Altered stool form - ranging from hard/lumpy stools (constipation-predominant) to loose/watery stools (diarrhea-predominant), classified using the Bristol stool chart 1, 3
• Altered stool passage including straining, urgency, or sensation of incomplete evacuation 1
• Abdominal distension and bloating that characteristically feels flat in the morning and progressively worsens throughout the day, peaking by late afternoon or evening 1, 2
• Passage of mucus in stools 1

Morning urgent defecation with multiple evacuations is particularly characteristic, where stool consistency changes from formed initially to progressively more liquid 4

Pain Characteristics Specific to IBS

• Pain worsened within 90 minutes after eating occurs in approximately 50% of patients, representing either an exaggerated colonic response to food or increased sensitivity to intestinal distension 4, 3
• Pain associated with looser and more frequent stools at onset 1
• Pain that improves with defecation is highly supportive of the diagnosis 1

Non-Gastrointestinal Symptoms That Strengthen the Diagnosis

These associated features significantly increase the probability of IBS and should not be dismissed as unrelated:

• Constant lethargy and poor sleep 1, 4, 2
• Lower back pain 4, 2
• Urinary symptoms including nocturia, frequency, urgency, and sensation of incomplete bladder emptying 4, 2
• Dyspareunia in women 4, 2
• Headache 4
• Chest pain 2
• Nausea 2

Important Comorbidities

The presence of these conditions substantially strengthens an IBS diagnosis:

• Fibromyalgia coexists in 20-50% of IBS patients, with lifetime rates of IBS in fibromyalgia reaching up to 77% 4, 3
• Chronic fatigue syndrome is present in 51% of patients 4
• Functional dyspepsia overlaps in 42-87% of IBS patients 4
• Temporomandibular joint dysfunction occurs in 64% of cases 4
• Chronic pelvic pain is present in 50% of patients 4

Psychological Features

• At least half of patients exhibit depression, anxiety, or hypochondria 1, 4
• Even non-consulters have greater psychological distress compared to individuals without IBS 4
• Anxiety, disturbed sleep, and associated lethargy may dominate the patient's existence in severe cases 1

Demographic Patterns

• IBS is approximately twice as common in women as men (prevalence 5.2-19.1% in women vs 1.5-12.1% in men using Rome I or three Manning criteria) 1
• More common in those younger than 45 years 1, 4
• Straining and passage of hard stools are more common in women, while frequent and loose stools are more common in men 1

Social Impact and Quality of Life

• Over 40% of patients avoid activities including work, traveling, socializing, sexual intercourse, and eating certain foods due to their symptoms 1
• Average work days lost per year are 14.8 compared with 8.7 in asymptomatic populations 1
• Symptoms such as bloating, fecal urgency, incontinence, diarrhea, and flatulence can substantially restrict social activities 1

Critical Red Flags That Suggest Alternative Diagnosis

These alarm features require immediate further investigation and suggest organic disease rather than IBS:

• Unintentional weight loss or anorexia 3, 2
• Rectal bleeding 1, 3, 2
• Nocturnal diarrhea or pain 1, 3
• Fever 3
• Anemia 1, 3
• Family history of inflammatory bowel disease or colorectal cancer 3, 2
• Short symptom duration (less than 2 years in younger patients) 1, 2

Postinfective Pattern

• 10-20% of patients relate onset of symptoms to an acute gastrointestinal illness 1

Diagnostic Approach in Primary Care

The diagnosis can be made safely in primary care based on typical symptoms, normal physical examination, and absence of alarm features, confirmed by observation over time 1, 4. This positive diagnostic approach avoids unnecessary testing while maintaining safety. 1

Essential initial testing should include complete blood count, C-reactive protein or ESR, celiac serology, and fecal calprotectin (<100 μg/g supports functional diagnosis) to exclude organic disease. 3