How should I manage sudden nocturnal abdominal cramps with a hot sensation and foul‑smelling sulfur/egg‑like gas causing severe discomfort?

Management of Nocturnal Abdominal Cramps with Hot Sensation and Sulfurous Gas

Start with a positive diagnosis of irritable bowel syndrome (IBS) if the patient is under 45 years old with typical symptoms (recurrent abdominal pain with altered bowel habit for ≥6 months) and no alarm features such as weight loss, rectal bleeding, fever, or nocturnal symptoms that wake them from sleep. 1, 2, 3

Initial Assessment and Diagnosis

• Obtain basic screening tests including full blood count, C-reactive protein or ESR, coeliac serology, and faecal calprotectin to exclude inflammatory bowel disease 2
• The sulfurous/egg-like gas suggests excessive production of hydrogen sulfide in the colon, which can occur with certain dietary triggers or altered gut microbiota 4, 5
• However, nocturnal symptoms that cause "extreme discomfort" are atypical for IBS and warrant further investigation, as IBS symptoms typically do not wake patients from sleep 1
• Consider testing for bile acid malabsorption with 23-seleno-25-homotaurocholic acid scanning or serum 7α-hydroxy-4-cholesten-3-one if there is a history of cholecystectomy or nocturnal diarrhea 1, 2

First-Line Dietary Management

Keep a two-week food and symptom diary to identify specific dietary triggers that provoke the sulfurous gas and nocturnal cramps. 1, 2, 3

Immediate Dietary Modifications:

• Reduce or eliminate high-sulfur foods including eggs, cruciferous vegetables (broccoli, cabbage, cauliflower), garlic, onions, red meat, and dairy products, as these are metabolized by colonic bacteria to produce hydrogen sulfide 4, 6, 5
• Avoid excessive intake of indigestible carbohydrates, fruits, caffeine, and alcohol, particularly in the evening 1, 2
• If dairy intake is substantial (>280 ml milk/day), trial lactose exclusion for 2 weeks 1
• Avoid eating within 4 hours of bedtime, as a short meal-to-sleep interval increases nocturnal reflux and gastrointestinal symptoms 7

Pharmacological Management for Nocturnal Cramps

Prescribe antispasmodic agents with anticholinergic properties such as dicyclomine taken 30-60 minutes before the evening meal and again at bedtime to prevent nocturnal cramping. 1, 2, 3

Alternative Options:

• Peppermint oil can be used as an alternative antispasmodic with fewer systemic side effects 1, 2, 3
• Common side effects of anticholinergics include dry mouth, visual disturbance, and dizziness 3

Second-Line Treatment if First-Line Fails

If symptoms persist after 3 months of dietary modification and antispasmodics, prescribe a tricyclic antidepressant (TCA) such as amitriptyline starting at 10 mg once nightly (taken 2-3 hours before bedtime) and titrate slowly by 10 mg weekly up to 30-50 mg once daily. 1, 2, 3

• TCAs have neuromodulatory and analgesic properties that reduce visceral hypersensitivity and alter gut motility independent of their antidepressant effects 2, 3
• TCAs are particularly effective when insomnia accompanies the gastrointestinal symptoms 3
• Continue TCAs for at least 6 months if the patient reports symptomatic improvement 2, 3

Advanced Dietary Intervention

If symptoms remain refractory, refer to a trained dietitian for a supervised trial of low FODMAP diet delivered in three phases: restriction (2-6 weeks), reintroduction, and personalization. 1, 2, 3

• The low FODMAP diet reduces fermentable carbohydrates that are metabolized by gut bacteria to produce gas, including hydrogen sulfide 1, 2
• This approach requires professional supervision to avoid nutritional deficits 2, 3

Psychological Therapies for Refractory Cases

Consider referral for IBS-specific cognitive behavioral therapy or gut-directed hypnotherapy if symptoms persist despite pharmacological treatment for 12 months. 1, 2, 3

• These brain-gut behavioral therapies are specifically designed for IBS and differ from standard psychological therapies 2, 3
• Relaxation therapy and stress management can reduce autonomic arousal and improve symptoms 1, 3

Critical Pitfalls to Avoid

• Do not ignore nocturnal symptoms that wake the patient from sleep, as this is an alarm feature requiring further investigation to exclude organic disease 1
• Avoid colonoscopy unless there are alarm symptoms (weight loss, rectal bleeding, anemia, family history of colon cancer) or atypical features suggesting microscopic colitis 1, 2, 3
• Do not perform hydrogen breath testing for small intestinal bacterial overgrowth in patients with typical IBS symptoms, as it has poor specificity 1
• Avoid IgG-based food elimination diets as they are not evidence-based 2, 3

When to Refer to Gastroenterology

Refer when there is diagnostic doubt, severe or refractory symptoms despite 12 months of treatment, nocturnal symptoms causing sleep disruption, or patient request. 1, 2, 3