What proof would you need to support your cause on a soldier malingering ?

Being sick is not against the UCMJ, but malingering is. Does it impact the mission enough to warrant your time spent on it? If so, proceed but tread lightly. No underhanded sneaky peaky or outright surveillance. You should be documenting it regularly but only facts. If he later is boarded for conduct or health it will be helpful. Partner with NCOIC or PSG and go from there. Get your ducks aligned first.

You can bring your concerns up to your command, the commander has a open line of communication with the Unit PA/ legal team and can bring up any concern regarding a malingering soldier to them. You aren’t a medical professional (PA), and any accusation of malingering to a soldier is threading on thin ice.

Once upon a time, a long time ago, I was put in charge of an Airman no one wanted to be in charge of. She was considered lazy, overweight, and constantly would go to sick-call complaining of headaches and fatigue. We all thought that she was the problem, especially since she didn't get along with her previous supervisor. Eventually she complained enough and got a medical discharge for chronic migraine headaches. We all thought this was just weak and pathetic since when she was around she always seemed fine. Well...two years later the real culprit appeared. Degenerative Multiple Sclerosis. She was 25 then. Seems like we were wrong. The bullying her, thinking she was a turd airman, lazy, etc. was all misplaced. She actually was sick. She committed suicide about 6 months after her diagnosis because she didn't want to be a burden on her two children. So maybe you stop and evaluate the situation a little more, be more objective in your judgments. Cause not everyone with frequent trips to sick call is lazy or weak. Some are actually sick.

I do not know if this would fly anymore.

Most often, if someone was malingering it was to get out of a field event, or force march. I used them as training aids. After consulting with the Battalion surgeon, any Marine that could go to the field without violating medical restrictions, did. Within the limits imposed by the Battalion Surgeon and supervised by the Battalion Medical Chief and Company Corpsmen the "sick, lame, and lazy" were treated as battlefield casualties.

Appropriate to the training event, they were used as simulated casualties who had to be found, retrieved, treated, evacuated, and transported to the Battalion Aid Station (BAS). A CP tent was set up outside the garrison Command Post as the "Battalion Aid Station." During field exercises the "casualties" were either in the field, or in garrison restricted to the CP tent. While in the garrison BAS, they rested and recovered under the loving care of the Battalion Officer of the Day and the Staff Duty, without distractions like TV, radio, etc. etc. No one went to their quarters, for the duration of the field exercise.

It seems that boredom has medicinal restorative properties.

I would take it in a different direction. First, it is the commander’s role to work with the medical team regarding the health of their Soldiers. So if you are not the Commander or 1SG I would push this one back to them. Second, if you are the Commander, then I would talk directly to the Doc and address this concern as you can get feedback from the doc regarding a way forward. Third, if this continues with no end and no clear cause, I would ask for a med board or referral to a specialist. Past that you are going to have an almost impossible task of proving malingering. I am speaking as a former Warrior Transition Unit Commander. You could also speak to legal but they will tell you to talk to the care team (doc).

My buddy in 10th Mountain used to have a BDE Physicians Assistant who used to be hooah, like SF or something. Whenever my buddy suspected or knew that Joe was faking it to go to sick call, he would call Hooah PA. If the Soldier was legitimately sick, Hooah PA would compassionately do his job, but if he sensed or knew that Joe was malingering, he would employ the following technique. "You said your stomach is hurting? How long has it been hurting? Oh no! This could be very dangerous! What I need to do (begins putting rubber gloves on while talking) is do a probe to determine if it is (insert some highly dangerous medical condition) or if it is (insert another highly dangerous medical condition). I need you to drop your pants and underwear, bend over and place your hands on the bench." Magically, Joe was instantaneously healed of whatever malady caused him to come to the Bn Aid Station. Take this war story and do with it what you will.

Short of the Soldier admitting it - it’s a tough nut to crack. Continue to document and see if it’s a pattern that occurs before major training events. Could be legit. As a Commander - I’ve never seen anyone prove malingering.

What case? You have a sick soldier or one that professes to be sick, you don’t know.
I assume that you are the boss. You don’t start with a hypothesis (soldier malingering), you investigate first, that keeps from clouding your judgement. If there are rumors cut them short, as in, “Knock it off!” Get to know the guy or gal, find out from them if there’s anything you can do to help them. That’s a good way to get them to open up, and get you the answer.

I would exercise caution here. I had a Soldier once who complained of the same thing. His squad leader wanted to get him for malingering - but I intervened. As a former NCO, I reminded the squad leader that we are not doctors and that I trusted that the Corporal was not a malingerer and that perhaps the Corporal doesn't even know why this was happening to him. Who would put themelves through that much pain or the trouble of being harassed if they truly didn't have a medical issue? I would say be supportive, show some human compassion and realize that your support might save a life - and someday you may find yourself seeking such compassion should you ever face a similar health issue. By the way, the Corporal in my unit had to be transferred to a specialized medical facility in another state and he never returned to us again - it took our base medical team 3 months to discover what was wrong with him, and the constant berating by his squad leader certainly didn't help him. I pray for you both - one, that your Soldier recovers and two, that you grow and mature as a leader to discover that with age comes experience and wisdom to help you become a better effective leader.

Still fuzzy on what catching him in the act looks like for stomach issues.

There is nothing to keep you from following up on an ill soldier. Not sure what you'd find. Sitting on the couch watching Maury looks the exact same with or with out stomach maladies. Unless he has Atomic Fireball wings from Buffalo Wild Wings or something. Or you catch him hooking up in his room during quarters....don't worry baby, I told them I had diarrhea....