Watts Sphincter of Oddi Dysfunction (SOD) & Irritable Bowel Syndrome (IBS)?

Sphincter of Oddi Dysfunction (SOD) and Irritable Bowel Syndrome (IBS) are two distinct gastrointestinal conditions that, in my case, frequently occur together and share overlapping features. While they affect different parts of the digestive system, both impact gut motility and digestive function — often flaring at the same time and complicating treatment strategies.

SOD affects a small muscular valve responsible for regulating the flow of bile and pancreatic enzymes into the small intestine. When the valve spasms or becomes narrowed, it can prevent digestive fluids from draining correctly, leading to pressure, inflammation, and complications such as chronic pancreatitis.

IBS is a functional gastrointestinal disorder involving abnormal gut motility and sensitivity. It causes changes in bowel habits without structural damage, but contributes to significant discomfort and adds an extra layer of instability to the digestive system.

These conditions are grouped together here because they frequently flare together and often require careful coordination when it comes to food, medication, and treatment — particularly when one condition’s treatment can exacerbate the other.

🤕 Watts The Symptoms?

SOD typically causes severe upper abdominal pain that radiates into the back, ribs, or right shoulder. The pain often presents after eating or taking opiate-based pain relief, and can mimic gallbladder or pancreatic attacks. In my case, the pain is intense, unpredictable, and — when SOD is flaring badly — is among the most excruciatingly painful of any of my conditions. It is frequently accompanied by:

• Nausea and vomiting
• Loss of appetite
• Bloating and pressure in the upper abdomen
• Tenderness in the mid or upper right abdomen
• Episodes of pancreatitis with associated symptoms (including pain under the left ribs, stabbing or burning sensations — especially when leaning forward or lying flat on your back)

This pain can last from hours to days and often does not respond well to standard pain management strategies — in fact, many pain relief medications are known to exacerbate SOD. It tends to flare following certain foods, medications, or procedures — but can also occur without warning.

IBS causes more diffuse lower abdominal pain or cramping, bloating, and changes in bowel habits — including constipation, diarrhoea, or alternating between the two. While not as severe as the pain from SOD, IBS symptoms are disruptive and can exacerbate overall gastrointestinal discomfort when both conditions flare-up together.

Together, these conditions can create a cycle of upper and lower abdominal pain, bloating, and nausea that is difficult to predict and even harder to treat — especially given that treatments for one often aggravate the other. Flares can also be triggered by broader system instability, particularly during MCAS or EoE flare-ups.

⚡ Watts The Triggers?

Both SOD and IBS can flare-up unpredictably, but there are certain triggers that consistently increase symptoms — and unfortunately, they don’t always respect boundaries between one condition and the other.

Known SOD triggers in my case include:

• Opiate-based pain relief
• Fatty or high-protein meals
• Certain medications that affect the smooth muscle (e.g. anticholinergics, some antiemetics)
• Procedures involving the upper GI or biliary system
• Stress or physical overexertion
• Surgical procedures and general anaesthetics
• An implanted neurostimulator — which was removed due to its electrodes stimulating the sphincter of Oddi and exacerbating biliary dyskinesia
• Even minor irritations — like a change in routine or temperature

IBS triggers are often dietary or stress-related, and include:

• Certain FODMAP foods (including onions, garlic, legumes)
• Large meals or eating too quickly
• Hormonal fluctuations
• Travel, disrupted routines, or inconsistent sleep
• Emotional or sensory overload

Flare-ups are also frequently worsened by other coexisting conditions. In particular:

System-wide instability (e.g., during fatigue, illness, or post-surgical recovery) tends to increase both SOD and IBS symptoms.

🩻 Watts The Diagnosis Process?

SOD was suspected after I continued to suffer severe biliary pain after my gallbladder was removed. I was readmitted to hospital just nine days post-op with worsening pain and abnormal liver and pancreatic enzyme levels. A specialist ERCP (Endoscopic Retrograde Cholangiopancreatography) was performed, which confirmed the diagnosis. Regular blood testing is also used to monitor liver functions and pancreatic enzymes, especially during SOD flare-ups.

IBS was diagnosed after other lower abdominal conditions were ruled out. I underwent a diagnostic laparoscopy to exclude causes such as endometriosis or structural abnormalities. Regular colonoscopies have been part of my care due to ongoing symptoms and a family history of bowel cancer and the discovery of a 4cm tubulovillous adenoma bowel polyp which required surgical removal at age 35. While IBS itself is a functional diagnosis, this level of screening and surveillance has been necessary to ensure that nothing more serious was being missed.

🩺 Watts The Management Team?

Both SOD and IBS require ongoing management and regular monitoring — often involving multiple specialists across gastroenterology and pain medicine. There’s no single specialist who manages every aspect, so coordination is essential.

In my case, the key team members include:

• Gastroenterologist – for diagnosis, endoscopic surveillance, ERCP procedures, and long-term management of upper and lower GI symptoms
• Colorectal Surgeon – involved in surgical removal of significant bowel polyps and management of structural issues
• Pain Specialist – for medication oversight and management of severe biliary pain, especially during flare-ups
• Dietitian – for nutritional support, FODMAP guidance, and avoiding food-related triggers
• GP – for day-to-day support, symptom tracking, prescription management, and coordinating referrals
• Immunologist – due to coexisting MCAS, which complicates medication tolerability and digestive reactivity
• Gastrointestinal Surgeon (Upper GI) – for post-cholecystectomy complications, SOD-related pain, and surgical planning if needed

Effective management requires individualising treatment strategies and anticipating how each intervention may affect both conditions — especially given that one condition’s treatment can easily trigger the other.

🧩 Related Conditions

SOD and IBS rarely exist in isolation — and in my case, they’re part of a broader web of overlapping diagnoses that affect digestion, pain regulation, and systemic stability. These include:

• Complex Regional Pain Syndrome (CRPS) & Chronic Refractory Pain
• Ehlers-Danlos Syndrome (EDS)
• Eosinophilic Esophagitis (EoE)
• Mast Cell Activation Syndrome (MCAS), Hereditary Alpha Tryptasemia (HaT) & Allergies
• Migraine & Headaches
• Postural Orthostatic Tachycardia Syndrome (POTS)
• Tinnitus
• Temporomandibular Joint Dysfunction (TMJD)

…You can also visit my blog — where I occasionally rant about my digestive system like it’s the person who used the last of the toilet paper and didn’t bother to replace the roll. Stories of coping, crashing, and coaxing this body through flare-up after flare-up … with occasional sparkle, strategic swearing, and stubborn survival.

You can also visit the Helpful Links page for resources and organisations I’ve found useful along the way.

Disclaimer:
I’m not a doctor — just someone with a lot of medical letters on my file and a few too many hospital wristbands. Everything shared on this site comes from my personal experience living with complex chronic conditions. It’s not medical advice, and it shouldn’t replace professional guidance. Always speak to your healthcare team before making any treatment decisions (especially if it involves sparkles, spreadsheets, or ice cream therapy).